G2Cdb::Gene report

Gene id
Gene symbol
Homo sapiens
G00000646 (Mus musculus)

Databases (8)

Curated Gene
OTTHUMG00000014913 (Vega human gene)
ENSG00000151914 (Ensembl human gene)
667 (Entrez Gene)
1060 (G2Cdb plasticity & disease)
DST (GeneCards)
113810 (OMIM)
Marker Symbol
HGNC:1090 (HGNC)
Protein Sequence
O94833 (UniProt)

Synonyms (9)

  • BP240
  • BPA
  • CATX-15
  • FLJ13425
  • FLJ21489
  • FLJ30627
  • FLJ32235
  • KIAA0728
  • MACF2

Literature (53)

Pubmed - other

  • BPAG1 isoform-b: complex distribution pattern in striated and heart muscle and association with plectin and alpha-actinin.

    Steiner-Champliaud MF, Schneider Y, Favre B, Paulhe F, Praetzel-Wunder S, Faulkner G, Konieczny P, Raith M, Wiche G, Adebola A, Liem RK, Langbein L, Sonnenberg A, Fontao L and Borradori L

    Clinic of Dermatology, Geneva University Hospital, Rue Micheli-du-Crest 24, 1211 Geneva, Switzerland.

    BPAG1-b is the major muscle-specific isoform encoded by the dystonin gene, which expresses various protein isoforms belonging to the plakin protein family with complex, tissue-specific expression profiles. Recent observations in mice with either engineered or spontaneous mutations in the dystonin gene indicate that BPAG1-b serves as a cytolinker important for the establishment and maintenance of the cytoarchitecture and integrity of striated muscle. Here, we studied in detail its distribution in skeletal and cardiac muscles and assessed potential binding partners. BPAG1-b was detectable in vitro and in vivo as a high molecular mass protein in striated and heart muscle cells, co-localizing with the sarcomeric Z-disc protein alpha-actinin-2 and partially with the cytolinker plectin as well as with the intermediate filament protein desmin. Ultrastructurally, like alpha-actinin-2, BPAG1-b was predominantly localized at the Z-discs, adjacent to desmin-containing structures. BPAG1-b was able to form complexes with both plectin and alpha-actinin-2, and its NH(2)-terminus, which contains an actin-binding domain, directly interacted with that of plectin and alpha-actinin. Moreover, the protein level of BPAG1-b was reduced in muscle tissues from plectin-null mutant mice versus wild-type mice. These studies provide new insights into the role of BPAG1-b in the cytoskeletal organization of striated muscle.

    Funded by: Austrian Science Fund FWF: P 17862, P 20744; NINDS NIH HHS: NS047711; Telethon: GGP04088

    Experimental cell research 2010;316;3;297-313

  • An EB1-binding motif acts as a microtubule tip localization signal.

    Honnappa S, Gouveia SM, Weisbrich A, Damberger FF, Bhavesh NS, Jawhari H, Grigoriev I, van Rijssel FJ, Buey RM, Lawera A, Jelesarov I, Winkler FK, Wüthrich K, Akhmanova A and Steinmetz MO

    Biomolecular Research, Structural Biology, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.

    Microtubules are filamentous polymers essential for cell viability. Microtubule plus-end tracking proteins (+TIPs) associate with growing microtubule plus ends and control microtubule dynamics and interactions with different cellular structures during cell division, migration, and morphogenesis. EB1 and its homologs are highly conserved proteins that play an important role in the targeting of +TIPs to microtubule ends, but the underlying molecular mechanism remains elusive. By using live cell experiments and in vitro reconstitution assays, we demonstrate that a short polypeptide motif, Ser-x-Ile-Pro (SxIP), is used by numerous +TIPs, including the tumor suppressor APC, the transmembrane protein STIM1, and the kinesin MCAK, for localization to microtubule tips in an EB1-dependent manner. Structural and biochemical data reveal the molecular basis of the EB1-SxIP interaction and explain its negative regulation by phosphorylation. Our findings establish a general "microtubule tip localization signal" (MtLS) and delineate a unifying mechanism for this subcellular protein targeting process.

    Cell 2009;138;2;366-76

  • BPAG1e maintains keratinocyte polarity through beta4 integrin-mediated modulation of Rac1 and cofilin activities.

    Hamill KJ, Hopkinson SB, DeBiase P and Jones JC

    Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, IL 60611, USA.

    alpha6beta4 integrin, a component of hemidesmosomes, also plays a role in keratinocyte migration via signaling through Rac1 to the actin-severing protein cofilin. Here, we tested the hypothesis that the beta4 integrin-associated plakin protein, bullous pemphigoid antigen 1e (BPAG1e) functions as a scaffold for Rac1/cofilin signal transduction. We generated keratinocyte lines exhibiting a stable knockdown in BPAG1e expression. Knockdown of BPAG1e does not affect expression levels of other hemidesmosomal proteins, nor the amount of beta4 integrin expressed at the cell surface. However, the amount of Rac1 associating with beta4 integrin and the activity of both Rac1 and cofilin are significantly lower in BPAG1e-deficient cells compared with wild-type keratinocytes. In addition, keratinocytes deficient in BPAG1e exhibit loss of front-to-rear polarity and display aberrant motility. These defects are rescued by inducing expression of constitutively active Rac1 or active cofilin. These data indicate that the BPAG1e is required for efficient regulation of keratinocyte polarity and migration by determining the activation of Rac1.

    Funded by: NIAMS NIH HHS: R01 AR054184

    Molecular biology of the cell 2009;20;12;2954-62

  • Vitamin D(3) inhibits expression of bullous pemphigoid antigen 1 through post-transcriptional mechanism without new protein synthesis.

    Yamamoto C, Tamai K, Nakano H, Matsuzaki Y, Kaneko T and Sawamura D

    Journal of dermatological science 2008;50;2;155-8

  • Serum levels of IgE anti-BP180 and anti-BP230 autoantibodies in patients with bullous pemphigoid.

    Ishiura N, Fujimoto M, Watanabe R, Nakashima H, Kuwano Y, Yazawa N, Echigo T, Okochi H and Tamaki K

    Department of Dermatology, Graduate School of Medicine, University of Tokyo, Bunkyo, Tokyo, Japan.

    Background: Bullous pemphigoid (BP) is a subepidermal blistering disease characterized by autoantibodies against the hemidesmosomal proteins, BP180 and BP230. NC16A, a non-collagenous stretch of the BP180 ectodomain is the primary target of pathogenic IgG antibodies. Whereas IgG anti-BP180 autoantibodies play a primary role in the pathogenesis, there is a growing number of data regarding the potential pathogenic roles of IgE class autoantibodies in BP.

    Objectives: To examine the levels of IgG and IgE autoantibodies against BP180 and BP230, and to investigate mutual association and clinical relevance.

    Methods: Sera obtained from 67BP patients and 36 healthy donors were subjected to ELISA assays to measure serum IgG and IgE levels of anti-BP180 and anti-BP230 antibodies.

    Results: IgG anti-BP180 antibodies were positive in 63 (94%) of 67BP patients. IgG anti-BP230, IgE anti-BP180, and IgE anti-BP230 antibodies were found in 48 (72%), 20 (30%) and 45 (67%), respectively. IgG anti-BP180 levels were correlated with the affected areas. IgG anti-BP230 antibodies tended to increase in proportion to elongation of disease duration. IgE anti-BP230 levels showed a strong association with local eosinophil accumulation, while the levels were reversely related with the affected areas in BP.

    Conclusions: IgE autoantibodies to BP180 and BP230 are detected at high frequencies in BP. IgE anti-BP230 antibodies may have a role in attracting eosinophils to the skin lesions.

    Journal of dermatological science 2008;49;2;153-61

  • Structural analysis of the plakin domain of bullous pemphigoid antigen1 (BPAG1) suggests that plakins are members of the spectrin superfamily.

    Jefferson JJ, Ciatto C, Shapiro L and Liem RK

    Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.

    Bullous pemphigoid antigen 1 (BPAG1) is a member of the plakin family of proteins. The plakins are multi-domain proteins that have been shown to interact with microtubules, actin filaments and intermediate filaments, as well as proteins found in cellular junctions. These interactions are mediated through different domains on the plakins. The interactions between plakins and components of specialized cell junctions such as desmosomes and hemidesmosomes are mediated through the so-called plakin domain, which is a common feature of the plakins. We report the crystal structure of a stable fragment from BPAG1, residues 226-448, defined by limited proteolysis of the whole plakin domain. The structure, determined by single-wavelength anomalous diffraction phasing from a selenomethionine-substituted crystal at 3.0 A resolution, reveals a tandem pair of triple helical bundles closely related to spectrin repeats. Based on this structure and analysis of sequence conservation, we propose that the architecture of plakin domains is defined by two pairs of spectrin repeats interrupted by a putative Src-Homology 3 (SH3) domain.

    Funded by: NIGMS NIH HHS: GM 62270, R01 GM062270; NINDS NIH HHS: NS 47711, R01 NS047711

    Journal of molecular biology 2007;366;1;244-57

  • Disrupted in Schizophrenia 1 Interactome: evidence for the close connectivity of risk genes and a potential synaptic basis for schizophrenia.

    Camargo LM, Collura V, Rain JC, Mizuguchi K, Hermjakob H, Kerrien S, Bonnert TP, Whiting PJ and Brandon NJ

    Merck Research Labs, Merck & Co., Boston, MA 02115, USA. miguel_camargo@merck.com

    Disrupted in Schizophrenia 1 (DISC1) is a schizophrenia risk gene associated with cognitive deficits in both schizophrenics and the normal ageing population. In this study, we have generated a network of protein-protein interactions (PPIs) around DISC1. This has been achieved by utilising iterative yeast-two hybrid (Y2H) screens, combined with detailed pathway and functional analysis. This so-called 'DISC1 interactome' contains many novel PPIs and provides a molecular framework to explore the function of DISC1. The network implicates DISC1 in processes of cytoskeletal stability and organisation, intracellular transport and cell-cycle/division. In particular, DISC1 looks to have a PPI profile consistent with that of an essential synaptic protein, which fits well with the underlying molecular pathology observed at the synaptic level and the cognitive deficits seen behaviourally in schizophrenics. Utilising a similar approach with dysbindin (DTNBP1), a second schizophrenia risk gene, we show that dysbindin and DISC1 share common PPIs suggesting they may affect common biological processes and that the function of schizophrenia risk genes may converge.

    Molecular psychiatry 2007;12;1;74-86

  • Global, in vivo, and site-specific phosphorylation dynamics in signaling networks.

    Olsen JV, Blagoev B, Gnad F, Macek B, Kumar C, Mortensen P and Mann M

    Center for Experimental BioInformatics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark.

    Cell signaling mechanisms often transmit information via posttranslational protein modifications, most importantly reversible protein phosphorylation. Here we develop and apply a general mass spectrometric technology for identification and quantitation of phosphorylation sites as a function of stimulus, time, and subcellular location. We have detected 6,600 phosphorylation sites on 2,244 proteins and have determined their temporal dynamics after stimulating HeLa cells with epidermal growth factor (EGF) and recorded them in the Phosida database. Fourteen percent of phosphorylation sites are modulated at least 2-fold by EGF, and these were classified by their temporal profiles. Surprisingly, a majority of proteins contain multiple phosphorylation sites showing different kinetics, suggesting that they serve as platforms for integrating signals. In addition to protein kinase cascades, the targets of reversible phosphorylation include ubiquitin ligases, guanine nucleotide exchange factors, and at least 46 different transcriptional regulators. The dynamic phosphoproteome provides a missing link in a global, integrative view of cellular regulation.

    Cell 2006;127;3;635-48

  • Current insights into the formation and breakdown of hemidesmosomes.

    Litjens SH, de Pereda JM and Sonnenberg A

    Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.

    Hemidesmosomes are multiprotein adhesion complexes that promote epithelial stromal attachment in stratified and complex epithelia. Modulation of their function is of crucial importance in a variety of biological processes, such as differentiation and migration of keratinocytes during wound healing and carcinoma invasion, in which cells become detached from the substrate and acquire a motile phenotype. Although much is known about the signaling potential of the alpha6beta4 integrin in carcinoma cells, the events that coordinate the disassembly of hemidesmosomes during differentiation and wound healing remain unclear. The binding of alpha6beta4 to plectin has a central role in hemidesmosome assembly and it is becoming clear that disrupting this interaction is a crucial event in hemidesmosome disassembly. In addition, further insight into the functional interplay between alpha3beta1 and alpha6beta4 has contributed to our understanding of hemidesmosome disassembly and cell migration.

    Trends in cell biology 2006;16;7;376-83

  • Interferon-gamma down-regulates expression of the 230-kDa bullous pemphigoid antigen gene (BPAG1) in epidermal keratinocytes via novel chimeric sequences of ISRE and GAS.

    Kaneko T, Tamai K, Matsuzaki Y, Yamazaki T, Nakano H, Kon A, Hashimoto I, Hanada K, Kaneda Y and Uitto J

    Department of Dermatology, Hirosaki University School of Medicine, Hirosaki, Japan.

    The 230-kDa bullous pemphigoid antigen (BPAG1) is an integral component of hemidesmosomes. We have previously reported that interferon-gamma (IFNgamma) inhibits the transcription of the BPAG1 gene (1). Here we investigated the target sequences of IFNgamma-signal transduction pathway in the BPAG1 promoter in epidermal keratinocytes. Transient transfections with 5'-deletion constructs of BPAG1 promoter-luciferase reporter gene plasmids in cultured normal human epidermal keratinocytes (NHEK) allowed us to narrow the DNA region containing IFNgamma inhibitory element (IGIE) to between -1 and -89, upstream from the transcription initiation site (+1). Homology search in this region identified a chimeric sequence, consisting of IFN-stimulated responsive element (ISRE) with a partial 7-bp sequence of IFNgamma activation site (GAS), as identified in the guanylate-binding protein (GBP) gene, inserted at its center. Functional analysis of IGIE, inserted in front of the heterologous thymidine kinase promoter, indicated that IGIE acts as a down-regulatory element of the promoter through IFNgamma-dependent signal pathway. Transient transfection studies with BPAG1 promoter-reporter gene constructs containing mutated IGIE (with TT to GG transversions in the region of 5'ISRE, GAS, and 3'ISRE) demonstrated that disruption of the ISRE sequences, but not GAS, markedly suppressed the BPAG1 basal promoter activity and resulted in attenuated IFNgamma response in keratinocytes. Our findings provide novel insight into the mechanism of IFNgamma regulation in keratinocyte differentiation and proliferation.

    Experimental dermatology 2006;15;4;308-14

  • Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes.

    Kimura K, Wakamatsu A, Suzuki Y, Ota T, Nishikawa T, Yamashita R, Yamamoto J, Sekine M, Tsuritani K, Wakaguri H, Ishii S, Sugiyama T, Saito K, Isono Y, Irie R, Kushida N, Yoneyama T, Otsuka R, Kanda K, Yokoi T, Kondo H, Wagatsuma M, Murakawa K, Ishida S, Ishibashi T, Takahashi-Fujii A, Tanase T, Nagai K, Kikuchi H, Nakai K, Isogai T and Sugano S

    Life Science Research Laboratory, Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, 185-8601, Japan.

    By analyzing 1,780,295 5'-end sequences of human full-length cDNAs derived from 164 kinds of oligo-cap cDNA libraries, we identified 269,774 independent positions of transcriptional start sites (TSSs) for 14,628 human RefSeq genes. These TSSs were clustered into 30,964 clusters that were separated from each other by more than 500 bp and thus are very likely to constitute mutually distinct alternative promoters. To our surprise, at least 7674 (52%) human RefSeq genes were subject to regulation by putative alternative promoters (PAPs). On average, there were 3.1 PAPs per gene, with the composition of one CpG-island-containing promoter per 2.6 CpG-less promoters. In 17% of the PAP-containing loci, tissue-specific use of the PAPs was observed. The richest tissue sources of the tissue-specific PAPs were testis and brain. It was also intriguing that the PAP-containing promoters were enriched in the genes encoding signal transduction-related proteins and were rarer in the genes encoding extracellular proteins, possibly reflecting the varied functional requirement for and the restricted expression of those categories of genes, respectively. The patterns of the first exons were highly diverse as well. On average, there were 7.7 different splicing types of first exons per locus partly produced by the PAPs, suggesting that a wide variety of transcripts can be achieved by this mechanism. Our findings suggest that use of alternate promoters and consequent alternative use of first exons should play a pivotal role in generating the complexity required for the highly elaborated molecular systems in humans.

    Genome research 2006;16;1;55-65

  • Experimental bullous pemphigoid generated in mice with an antigenic epitope of the human hemidesmosomal protein BP230.

    Kiss M, Husz S, Jánossy T, Marczinovits I, Molnár J, Korom I and Dobozy A

    Department of Dermatology and Allergology, University of Szeged, H-6720 Szeged, Korányi fasor 6, Hungary. km@derma.szote.u-szeged.hu

    Bullous pemphigoid (BP) is an IgG-mediated autoimmune blistering disease that targets the hemidesmosomal proteins BP230 and BP180. To investigate the pathogenic role of anti-BP230 antibodies, rabbit polyclonal antibodies were generated against an antigenic sequence of the human BP230 antigen (BPAG 1, 2479-2499), which shows 67% homology in the human and the mouse BP230. Purified IgG from the rabbit anti-serum was transferred subcutaneously into the dorsal skin of neonatal isogeneic CBA/Ca (CBA) mice in a dose of 5 mg (n=7) or 1.2 mg IgG/50 microl (n=16). After 24 h, 1 of the mice injected with 5 mg IgG exhibited blisters, but the dorsal skin of all 7 of them was erythematous, and gentle friction produced a fine persistent wrinkling of the epidermis in 4 mice. The mice injected with 1.2 mg IgG developed less severe symptoms. Immunohistological examinations revealed linear rabbit IgG and mouse C3 depositions along the basement membrane of the perilesional skin and subepidermal blister formation. An intradermal inflammatory reaction (granulocyte infiltration) was also detected. None of these symptoms was seen in mice injected with IgG from a control rabbit anti-serum. These findings demonstrate that antibodies against BP230 can elicit the clinical and immunopathological features of BP in neonatal mice, suggesting that anti-BP230 antibodies may possibly play a pathogenic role in this disease.

    Journal of autoimmunity 2005;24;1;1-10

  • Transcriptional regulation of the 230-kDa bullous pemphigoid antigen gene expression by interferon regulatory factor 1 and interferon regulatory factor 2 in normal human epidermal keratinocytes.

    Odanagi M, Kikuchi Y, Yamazaki T, Kaneko T, Nakano H, Tamai K, Uitto J, Vitto J and Hanada K

    Department of Dermatology, Hirosaki University School of Medicine, Aomori, Japan. derma@cc.hirosaki-u.ac.jp

    Interferon regulatory factors (IRFs) are a family of transcriptional factors induced by interferon-gamma (IFN-gamma). Recent studies have indicated that the deregulation of IRF system in keratinocytes is responsible, at least in part, for aberrant proliferation and the differentiation of the psoriatic epidermis. Previously, we reported that the expression of 230-kDa bullous pemphigoid antigen (BPAG1) gene, which is strictly restricted to basal keratinocytes, is transcriptionally suppressed by IFN-gamma, but the contribution of IRFs in such suppression is still unclear. In this study, we investigated the role of IRFs in the regulation of BPAG1 gene expression. Computer analysis identified IRF1 and IRF2 consensus sequences between -135 and -123 on BPAG1 promoter region. Transient transfection studies with BPAG1 promoter-luciferase reporter gene plasmids and IRF1 and IRF2 expression plasmids revealed that IRF1 and IRF2 directly down-regulated BPAG1 gene transcription in cultured normal human epidermal keratinocytes. Several sets of gel retardation assays with the BPAG1-IRF binding sequence as a probe indicated that IRF1 and IRF2 could bind to the BPAG1-IRF sequence, but some other protein(s), which was induced by IFN-gamma stimulation and possessed binding activity to IRF consensus sequence, showed preferential binding to the BPAG1-IRF sequence. Our results suggest that IFN-gamma-IRF system is involved in BPAG1 gene regulation in type-1 helper T-cell inflammatory skin conditions, such as psoriasis vulgaris.

    Experimental dermatology 2004;13;12;773-9

  • The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

    Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Morrin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J and MGC Project Team

    The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline.

    Funded by: PHS HHS: N01-C0-12400

    Genome research 2004;14;10B;2121-7

  • Sequence comparison of human and mouse genes reveals a homologous block structure in the promoter regions.

    Suzuki Y, Yamashita R, Shirota M, Sakakibara Y, Chiba J, Mizushima-Sugano J, Nakai K and Sugano S

    Human Genome Center, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan. ysuzuki@ims.u-tokyo.ac.jp

    Comparative sequence analysis was carried out for the regions adjacent to experimentally validated transcriptional start sites (TSSs), using 3324 pairs of human and mouse genes. We aligned the upstream putative promoter sequences over the 1-kb proximal regions and found that the sequence conservation could not be further extended at, on average, 510 bp upstream positions of the TSSs. This discontinuous manner of the sequence conservation revealed a "block" structure in about one-third of the putative promoter regions. Consistently, we also observed that G+C content and CpG frequency were significantly different inside and outside the blocks. Within the blocks, the sequence identity was uniformly 65% regardless of their length. About 90% of the previously characterized transcription factor binding sites were located within those blocks. In 46% of the blocks, the 5' ends were bounded by interspersed repetitive elements, some of which may have nucleated the genomic rearrangements. The length of the blocks was shortest in the promoters of genes encoding transcription factors and of genes whose expression patterns are brain specific, which suggests that the evolutional diversifications in the transcriptional modulations should be the most marked in these populations of genes.

    Genome research 2004;14;9;1711-8

  • Functional proteomics mapping of a human signaling pathway.

    Colland F, Jacq X, Trouplin V, Mougin C, Groizeleau C, Hamburger A, Meil A, Wojcik J, Legrain P and Gauthier JM

    Hybrigenics SA, 75014 Paris, France. fcolland@hybrigenics.fr

    Access to the human genome facilitates extensive functional proteomics studies. Here, we present an integrated approach combining large-scale protein interaction mapping, exploration of the interaction network, and cellular functional assays performed on newly identified proteins involved in a human signaling pathway. As a proof of principle, we studied the Smad signaling system, which is regulated by members of the transforming growth factor beta (TGFbeta) superfamily. We used two-hybrid screening to map Smad signaling protein-protein interactions and to establish a network of 755 interactions, involving 591 proteins, 179 of which were poorly or not annotated. The exploration of such complex interaction databases is improved by the use of PIMRider, a dedicated navigation tool accessible through the Web. The biological meaning of this network is illustrated by the presence of 18 known Smad-associated proteins. Functional assays performed in mammalian cells including siRNA knock-down experiments identified eight novel proteins involved in Smad signaling, thus validating this integrated functional proteomics approach.

    Genome research 2004;14;7;1324-32

  • Role of binding of plectin to the integrin beta4 subunit in the assembly of hemidesmosomes.

    Koster J, van Wilpe S, Kuikman I, Litjens SH and Sonnenberg A

    The Netherlands Cancer Institute, Division of Cell Biology, 1066 CX Amsterdam, The Netherlands.

    We have previously shown that plectin is recruited into hemidesmosomes through association of its actin-binding domain (ABD) with the first pair of fibronectin type III (FNIII) repeats and a small part of the connecting segment (residues 1328-1355) of the integrin beta4 subunit. Here, we show that two proline residues (P1330 and P1333) in this region of the connecting segment are critical for supporting beta4-mediated recruitment of plectin. Additional binding sites for the plakin domain of plectin on beta4 were identified in biochemical and yeast two-hybrid assays. These sites are located at the end of the connecting segment (residues 1383-1436) and in the region containing the fourth FNIII repeat and the C-tail (residues 1570-1752). However, in cells, these additional binding sites cannot induce the assembly of hemidesmosomes without the interaction of the plectin-ABD with beta4. Because the additional plectin binding sites overlap with sequences that mediate an intramolecular association of the beta4 cytoplasmic domain, we propose that they are not accessible for binding and need to become exposed as the result of the binding of the plectin-ABD to beta4. Furthermore, these additional binding sites might be necessary to position the beta4 cytoplasmic domain for an optimal interaction with other hemidesmosomal components, thereby increasing the efficiency of hemidesmosome assembly.

    Molecular biology of the cell 2004;15;3;1211-23

  • Complete sequencing and characterization of 21,243 full-length human cDNAs.

    Ota T, Suzuki Y, Nishikawa T, Otsuki T, Sugiyama T, Irie R, Wakamatsu A, Hayashi K, Sato H, Nagai K, Kimura K, Makita H, Sekine M, Obayashi M, Nishi T, Shibahara T, Tanaka T, Ishii S, Yamamoto J, Saito K, Kawai Y, Isono Y, Nakamura Y, Nagahari K, Murakami K, Yasuda T, Iwayanagi T, Wagatsuma M, Shiratori A, Sudo H, Hosoiri T, Kaku Y, Kodaira H, Kondo H, Sugawara M, Takahashi M, Kanda K, Yokoi T, Furuya T, Kikkawa E, Omura Y, Abe K, Kamihara K, Katsuta N, Sato K, Tanikawa M, Yamazaki M, Ninomiya K, Ishibashi T, Yamashita H, Murakawa K, Fujimori K, Tanai H, Kimata M, Watanabe M, Hiraoka S, Chiba Y, Ishida S, Ono Y, Takiguchi S, Watanabe S, Yosida M, Hotuta T, Kusano J, Kanehori K, Takahashi-Fujii A, Hara H, Tanase TO, Nomura Y, Togiya S, Komai F, Hara R, Takeuchi K, Arita M, Imose N, Musashino K, Yuuki H, Oshima A, Sasaki N, Aotsuka S, Yoshikawa Y, Matsunawa H, Ichihara T, Shiohata N, Sano S, Moriya S, Momiyama H, Satoh N, Takami S, Terashima Y, Suzuki O, Nakagawa S, Senoh A, Mizoguchi H, Goto Y, Shimizu F, Wakebe H, Hishigaki H, Watanabe T, Sugiyama A, Takemoto M, Kawakami B, Yamazaki M, Watanabe K, Kumagai A, Itakura S, Fukuzumi Y, Fujimori Y, Komiyama M, Tashiro H, Tanigami A, Fujiwara T, Ono T, Yamada K, Fujii Y, Ozaki K, Hirao M, Ohmori Y, Kawabata A, Hikiji T, Kobatake N, Inagaki H, Ikema Y, Okamoto S, Okitani R, Kawakami T, Noguchi S, Itoh T, Shigeta K, Senba T, Matsumura K, Nakajima Y, Mizuno T, Morinaga M, Sasaki M, Togashi T, Oyama M, Hata H, Watanabe M, Komatsu T, Mizushima-Sugano J, Satoh T, Shirai Y, Takahashi Y, Nakagawa K, Okumura K, Nagase T, Nomura N, Kikuchi H, Masuho Y, Yamashita R, Nakai K, Yada T, Nakamura Y, Ohara O, Isogai T and Sugano S

    Helix Research Institute, 1532-3 Yana, Kisarazu, Chiba 292-0812, Japan.

    As a base for human transcriptome and functional genomics, we created the "full-length long Japan" (FLJ) collection of sequenced human cDNAs. We determined the entire sequence of 21,243 selected clones and found that 14,490 cDNAs (10,897 clusters) were unique to the FLJ collection. About half of them (5,416) seemed to be protein-coding. Of those, 1,999 clusters had not been predicted by computational methods. The distribution of GC content of nonpredicted cDNAs had a peak at approximately 58% compared with a peak at approximately 42%for predicted cDNAs. Thus, there seems to be a slight bias against GC-rich transcripts in current gene prediction procedures. The rest of the cDNAs unique to the FLJ collection (5,481) contained no obvious open reading frames (ORFs) and thus are candidate noncoding RNAs. About one-fourth of them (1,378) showed a clear pattern of splicing. The distribution of GC content of noncoding cDNAs was narrow and had a peak at approximately 42%, relatively low compared with that of protein-coding cDNAs.

    Nature genetics 2004;36;1;40-5

  • Bpag1 localization to actin filaments and to the nucleus is regulated by its N-terminus.

    Young KG, Pool M and Kothary R

    Ottawa Health Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6, and Center for Neuromuscular Disease, and Departments of Cellular and Molecular Medicine, and Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5.

    Plakins are a family of giant cytoskeleton binding proteins. One member of this group is bullous pemphigoid antigen 1 (Bpag1)/dystonin, which has neuronal and muscle isoforms that consist of actin-binding and microtubule-binding domains at either end separated by a plakin domain and several spectrin repeats. The better-characterized epithelial isoform has only the plakin domain in common with the neuronal and muscle isoforms. Here, we have analyzed the localization of muscle/neuronal (Bpag1a/b) isoforms and the epithelial (Bpag1e) isoform within C2C12 myoblast cells. Although an antibody specific to Bpag1a/b isoform 2 detected protein co-aligning actin stress fibers, this same antibody and two Bpag1e antibodies predominantly detected protein in the nuclei. A Bpag1a/b isoform 2 N-terminal fusion protein containing the plakin domain also localized to actin stress fibers and to nuclei. Within the plakin domain, we characterized a functional nuclear localization signal, which was responsible for localization of the fusion protein to the nucleus. Bpag1a/b isoform 1 N-terminal fusion proteins differed in their interaction with the actin cytoskeleton and with their ability to localize to the nucleus, suggesting that Bpag1 isoforms with different N-termini have differing roles. These results show the importance of N-terminal domains in dictating the localization and function of Bpag1 isoforms. We provide the first indication that Bpag1 is not strictly a cytoplasmic/membrane protein but that it can also localize to the nucleus.

    Journal of cell science 2003;116;Pt 22;4543-55

  • BPAG1n4 is essential for retrograde axonal transport in sensory neurons.

    Liu JJ, Ding J, Kowal AS, Nardine T, Allen E, Delcroix JD, Wu C, Mobley W, Fuchs E and Yang Y

    Department of Neurology, Stanford University School of Medicine, Stanford, CA 94305-5489, USA. yanmin.yang@stanford.edu

    Disruption of the BPAG1 (bullous pemphigoid antigen 1) gene results in progressive deterioration in motor function and devastating sensory neurodegeneration in the null mice. We have previously demonstrated that BPAG1n1 and BPAG1n3 play important roles in organizing cytoskeletal networks in vivo. Here, we characterize functions of a novel BPAG1 neuronal isoform, BPAG1n4. Results obtained from yeast two-hybrid screening, blot overlay binding assays, and coimmunoprecipitations demonstrate that BPAG1n4 interacts directly with dynactin p150Glued through its unique ezrin/radixin/moesin domain. Studies using double immunofluorescent microscopy and ultrastructural analysis reveal physiological colocalization of BPAG1n4 with dynactin/dynein. Disruption of the interaction between BPAG1n4 and dynactin results in severe defects in retrograde axonal transport. We conclude that BPAG1n4 plays an essential role in retrograde axonal transport in sensory neurons. These findings might advance our understanding of pathogenesis of axonal degeneration and neuronal death.

    Funded by: NIA NIH HHS: AG16999, R01 AG016999; NIAMS NIH HHS: AR27883, R01 AR027883, R37 AR027883; NINDS NIH HHS: K02 NS043281, NS24054, NS38869, NS42791, NS43281, R01 NS024054, R01 NS038869, R01 NS042791

    The Journal of cell biology 2003;163;2;223-9

  • The DNA sequence and analysis of human chromosome 6.

    Mungall AJ, Palmer SA, Sims SK, Edwards CA, Ashurst JL, Wilming L, Jones MC, Horton R, Hunt SE, Scott CE, Gilbert JG, Clamp ME, Bethel G, Milne S, Ainscough R, Almeida JP, Ambrose KD, Andrews TD, Ashwell RI, Babbage AK, Bagguley CL, Bailey J, Banerjee R, Barker DJ, Barlow KF, Bates K, Beare DM, Beasley H, Beasley O, Bird CP, Blakey S, Bray-Allen S, Brook J, Brown AJ, Brown JY, Burford DC, Burrill W, Burton J, Carder C, Carter NP, Chapman JC, Clark SY, Clark G, Clee CM, Clegg S, Cobley V, Collier RE, Collins JE, Colman LK, Corby NR, Coville GJ, Culley KM, Dhami P, Davies J, Dunn M, Earthrowl ME, Ellington AE, Evans KA, Faulkner L, Francis MD, Frankish A, Frankland J, French L, Garner P, Garnett J, Ghori MJ, Gilby LM, Gillson CJ, Glithero RJ, Grafham DV, Grant M, Gribble S, Griffiths C, Griffiths M, Hall R, Halls KS, Hammond S, Harley JL, Hart EA, Heath PD, Heathcott R, Holmes SJ, Howden PJ, Howe KL, Howell GR, Huckle E, Humphray SJ, Humphries MD, Hunt AR, Johnson CM, Joy AA, Kay M, Keenan SJ, Kimberley AM, King A, Laird GK, Langford C, Lawlor S, Leongamornlert DA, Leversha M, Lloyd CR, Lloyd DM, Loveland JE, Lovell J, Martin S, Mashreghi-Mohammadi M, Maslen GL, Matthews L, McCann OT, McLaren SJ, McLay K, McMurray A, Moore MJ, Mullikin JC, Niblett D, Nickerson T, Novik KL, Oliver K, Overton-Larty EK, Parker A, Patel R, Pearce AV, Peck AI, Phillimore B, Phillips S, Plumb RW, Porter KM, Ramsey Y, Ranby SA, Rice CM, Ross MT, Searle SM, Sehra HK, Sheridan E, Skuce CD, Smith S, Smith M, Spraggon L, Squares SL, Steward CA, Sycamore N, Tamlyn-Hall G, Tester J, Theaker AJ, Thomas DW, Thorpe A, Tracey A, Tromans A, Tubby B, Wall M, Wallis JM, West AP, White SS, Whitehead SL, Whittaker H, Wild A, Willey DJ, Wilmer TE, Wood JM, Wray PW, Wyatt JC, Young L, Younger RM, Bentley DR, Coulson A, Durbin R, Hubbard T, Sulston JE, Dunham I, Rogers J and Beck S

    The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. ajm@sanger.ac.uk

    Chromosome 6 is a metacentric chromosome that constitutes about 6% of the human genome. The finished sequence comprises 166,880,988 base pairs, representing the largest chromosome sequenced so far. The entire sequence has been subjected to high-quality manual annotation, resulting in the evidence-supported identification of 1,557 genes and 633 pseudogenes. Here we report that at least 96% of the protein-coding genes have been identified, as assessed by multi-species comparative sequence analysis, and provide evidence for the presence of further, otherwise unsupported exons/genes. Among these are genes directly implicated in cancer, schizophrenia, autoimmunity and many other diseases. Chromosome 6 harbours the largest transfer RNA gene cluster in the genome; we show that this cluster co-localizes with a region of high transcriptional activity. Within the essential immune loci of the major histocompatibility complex, we find HLA-B to be the most polymorphic gene on chromosome 6 and in the human genome.

    Nature 2003;425;6960;805-11

  • 230-kDa and 190-kDa proteins in addition to desmoglein 1 as immunological targets in a subset of pemphigus foliaceus with a combined cell-surface and basement membrane zone immune staining pattern.

    Karlhofer FM, Hashimoto T, Slupetzky K, Kiss M, Liu Y, Amagai M, Pieczkowski F, Foedinger D, Kirnbauer R and Stingl G

    Division of Immunology, Allergy and Infectious Diseases, Department of Dermatology, University of Vienna Medical School, General Hospital, Vienna, Austria. Franz.Karlhofer@akh-wien.ac.at

    Pemphigus erythematosus, initially described as a combination of pemphigus with lupus erythematosus, and pemphigus foliaceus are now frequently considered localized and generalized variants of superficial pemphigus. Yet diagnostic criteria for pemphigus erythematosus remain controversial. Distinct from pemphigus foliaceus, pemphigus erythematosus displays immune depositions at the dermal-epidermal junction, which suggests additional immunopathological mechanisms. We present three patients with clinical and histopathologic signs of superficial pemphigus, who all exhibited an immunomorphology characteristic of pemphigus erythematosus. Complement depositions in a granular-linear fashion were consistently found at the dermal-epidermal junction besides in vivo bound and circulating antikeratinocyte cell-surface autoantibodies. Histopathology showed subcorneal acantholysis, and all sera contained antidesmoglein 1 but not antidesmoglein 3 autoantibodies detected by enzyme-linked immunosorbent assays (ELISA). Additional autoantibodies against a 230-kDa protein and against a 190-kDa protein comigrating with bullous pemphigoid antigen 1 (BP230) and periplakin, respectively, were present in all the patients' sera. As two sera specifically reacted with BP230 by ELISA, the presence of BP230-specific autoantibodies could be associated with dermal-epidermal immune staining in these patients. In pemphigus erythematosus, dermal-epidermal immune staining is generally attributed to the deposition of immune complexes, while the presence of BP230-specific autoantibodies has not been reported in this disease previously. Perhaps, the unique autoantibody profile of the patients in the study permits discrimination between patients with superficial pemphigus that display additional dermal-epidermal immune staining from those with conventional pemphigus foliaceus on a molecular basis. Further studies will be required to substantiate the frequency of this occurrence and to unravel its pathogenic significance.

    Experimental dermatology 2003;12;5;646-54

  • Interaction of the bullous pemphigoid antigen 1 (BP230) and desmoplakin with intermediate filaments is mediated by distinct sequences within their COOH terminus.

    Fontao L, Favre B, Riou S, Geerts D, Jaunin F, Saurat JH, Green KJ, Sonnenberg A and Borradori L

    Department of Dermatology, University Hospital, Geneva, Switzerland CH-1211.

    The bullous pemphigoid antigen 1 (BP230) and desmoplakin (DP) are members of the plakin protein family of cytolinkers. Despite their homology, their COOH termini selectively bind distinct intermediate filaments (IFs). We studied sequences within their COOH termini required for their interaction with the epidermal keratins K5/K14, the simple epithelial keratins K8/K18, and type III IF vimentin by yeast three-hybrid, cell transfection, and overlay assays. The results indicate that BP230 interacts with K5/K14 but not with K8/K18 or vimentin via a region encompassing both the B and C subdomains and the COOH extremity, including a COOH-terminal eight-amino-acid stretch. In contrast, the C subdomain with the COOH-terminal extremity of DP interacts with K5/K14 and K8/K18, and its linker region is able to associate with K8/K18 and vimentin. Furthermore, the potential of DP to interact with IF proteins in yeast seems to be regulated by phosphorylation of Ser 2849 within its COOH terminus. Strikingly, BP230 and DP interacted with cytokeratins only when both type I and type II keratins were present. The head and tail domains of K5/K14 keratins were dispensable for their interaction with BP230 or DP. On the basis of our findings, we postulate that (1) the binding specificity of plakins for various IF proteins depends on their linker region between the highly homologous B and C subdomains and their COOH extremity and (2) the association of DP and BP230 with both epidermal and simple keratins is critically affected by the tertiary structure induced by heterodimerization and involves recognition sites located primarily in the rod domain of these keratins.

    Funded by: NIAMS NIH HHS: R01 AR043380

    Molecular biology of the cell 2003;14;5;1978-92

  • Keratinocyte responsive element 3: analysis of a keratinocyte-specific regulatory sequence in the 230-kDa bullous pemphigoid antigen gene promoter.

    Matsuzaki Y, Tamai K, Kon A, Sawamura D, Uitto J and Hashimoto I

    Department of Dermatology, Hirosaki University School of Medicine, Hirosaki, Japan. Yasushi.Matsuzaki@mail.tju.edu

    The 230-kDa bullous pemphigoid antigen gene is expressed primarily, if not exclusively, in basal keratinocytes of the epidermis. Keratinocyte responsive element 3, a cis-element at position -216 to -197 of the human 230-kDa bullous pemphigoid antigen gene promoter, confers tissue-specific expression to this gene (Tamai et al: J Biol Chem 270:7609-7614, 1995). In this study, we investigated the functional characteristics of keratinocyte responsive element 3 on the 230-kDa bullous pemphigoid antigen gene core promoter by transient transfections of cultured normal human keratinocytes and normal human fibroblasts, as well as of lung carcinoma (A549), osteosarcoma (OST), and gastric adenocarcinoma (GT3TKB) cell lines. A 230-kDa bullous pemphigoid antigen gene core promoter/luciferase reporter gene plasmid construct, pBPL, was modified to develop a series of constructs (pKBPL-p4KBPL), which have insertions of one, two, three, or four tandem repeats of keratinocyte responsive element 3, and these plasmids were used in transient transfections of the cultured cells. The promoter activities of pKBPL-p4KBPL constructs, relative to pBPL, in normal human keratinocytes were 7.6-, 15.5-, 4.6-, and 2.7-fold higher, respectively, whereas no upregulatory effect by keratinocyte responsive element 3 insertion was observed in other cell lines tested. prKBPL, a plasmid constructed with keratinocyte responsive element 3 in reverse orientation, showed essentially no activity in normal human keratinocytes. Insertion of a random 20 bp sequence between keratinocyte responsive element 3 and the 230-kDa bullous pemphigoid antigen gene core promoter resulted in about 40% reduction of luciferase activity in normal human keratinocytes. These data suggest that keratinocyte responsive element 3 functions as a position-, copy number-, and orientation-dependent cis-element contributing to tissue-specific regulation of the 230-kDa bullous pemphigoid antigen gene.

    Funded by: NIAMS NIH HHS: P01 AR38923

    The Journal of investigative dermatology 2003;120;2;308-12

  • Analysis of the interactions between BP180, BP230, plectin and the integrin alpha6beta4 important for hemidesmosome assembly.

    Koster J, Geerts D, Favre B, Borradori L and Sonnenberg A

    The Netherlands Cancer Institute, Division of Cell Biology, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.

    Hemidesmosomes (HDs) are multi-protein complexes that promote stable adhesion of epithelial cells to the underlying extracellular matrix. We assessed the interactions between different hemidesmosomal components with each other, mapped the binding sites and studied the importance of these interactions for HD assembly in yeast two-hybrid and cell-transfection assays. The results show that: (1) bullous pemphigoid antigen (BP) 180 binds not only to BP230, but also to plectin. The interactions between these proteins are facilitated by the Y subdomain in the N-terminal plakin domain of BP230 and plectin, and residues 145-230 of the cytoplasmic domain of BP180; (2) different, but overlapping, sequences on BP180 mediate binding to beta4, which, in turn associates with BP180 via its third fibronectin type III repeat; (3) sequences in the N-terminal extremity of BP230 mediate its binding to beta4, which requires the C-terminal end of the connecting segment up to the fourth FNIII repeat of the beta4 subunit. (4) Finally, cell-transfection studies showed that the localization of BP230 into hemidesmosome-like structures depends on its Z-Y subdomains as well as on the availability of BP180. By having further uncovered interactions between various hemidesmosomal components, mapped the involved binding sites and dissected a hierarchy of interactions relevant for their topogenic fate, our findings give novel insights into the molecular organization of hemidesmosomes.

    Journal of cell science 2003;116;Pt 2;387-99

  • Protein-protein interactions between large proteins: two-hybrid screening using a functionally classified library composed of long cDNAs.

    Nakayama M, Kikuno R and Ohara O

    Department of Human Gene Research, Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan. nmanabu@kazusa.or.jp

    Large proteins have multiple domains that are potentially capable of binding many kinds of partners. It is conceivable, therefore, that such proteins could function as an intricate framework of assembly protein complexes. To comprehensively study protein-protein interactions between large KIAA proteins, we have constructed a library composed of 1087 KIAA cDNA clones based on prior functional classifications done in silico. We were guided by two principles that raise the success rate for detecting interactions per tested combination: we avoided testing low-probability combinations, and reduced the number of potential false negatives that arise from the fact that large proteins cannot reliably be expressed in yeast. The latter was addressed by constructing a cDNA library comprised of random fragments encoding large proteins. Cytoplasmic domains of KIAA transmembrane proteins (>1000 amino acids) were used as bait for yeast two-hybrid screening. Our analyses reveal that several KIAA proteins bearing a transmembrane region have the capability of binding to other KIAA proteins containing domains (e.g., PDZ, SH3, rhoGEF, and spectrin) known to be localized to highly specialized submembranous sites, indicating that they participate in cellular junction formation, receptor or channel clustering, and intracellular signaling events. Our representative library should be a very useful resource for detecting previously unidentified interactions because it complements conventional expression libraries, which seldom contain large cDNAs.

    Genome research 2002;12;11;1773-84

  • Construction of expression-ready cDNA clones for KIAA genes: manual curation of 330 KIAA cDNA clones.

    Nakajima D, Okazaki N, Yamakawa H, Kikuno R, Ohara O and Nagase T

    Kazusa DNA Research Institute, Kisarazu, Chiba, Japan.

    We have accumulated information on protein-coding sequences of uncharacterized human genes, which are known as KIAA genes, through cDNA sequencing. For comprehensive functional analysis of the KIAA genes, it is necessary to prepare a set of cDNA clones which direct the synthesis of functional KIAA gene products. However, since the KIAA cDNAs were derived from long mRNAs (> 4 kb), it was not expected that all of them were full-length. Thus, as the first step toward preparing these clones, we evaluated the integrity of protein-coding sequences of KIAA cDNA clones through comparison with homologous protein entries in the public database. As a result, 1141 KIAA cDNAs had at least one homologous entry in the database, and 619 of them (54%) were found to be truncated at the 5' and/or 3' ends. In this study, 290 KIAA cDNA clones were tailored to be full-length or have considerably longer sequences than the original clones by isolating additional cDNA clones and/or connected parts of additional cDNAs or PCR products of the missing portion to the original cDNA clone. Consequently, 265, 8, and 17 predicted CDSs of KIAA cDNA clones were increased in the amino-, carboxy-, and both terminal sequences, respectively. In addition, 40 cDNA clones were modified to remove spurious interruption of protein-coding sequences. The total length of the resultant extensions at amino- and carboxy-terminals of KIAA gene products reached 97,000 and 7,216 amino acid residues, respectively, and various protein domains were found in these extended portions.

    DNA research : an international journal for rapid publication of reports on genes and genomes 2002;9;3;99-106

  • Novel alternative splicings of BPAG1 (bullous pemphigoid antigen 1) including the domain structure closely related to MACF (microtubule actin cross-linking factor).

    Okumura M, Yamakawa H, Ohara O and Owaribe K

    Unit of Biosystems, Graduate School of Human Informatics, Nagoya University, Nagoya 464-8601, Japan. masayo@info.human.nagoya-u.ac.jp

    BPAG1 (bullous pemphigoid antigen 1) was originally identified as a 230-kDa hemidesmosomal protein and belongs to the plakin family, because it consists of a plakin domain, a coiled-coil rod domain and a COOH-terminal intermediate filament binding domain. To date, alternatively spliced products of BPAG1, BPAG1e, and BPAG1n are known. BPAG1e is expressed in epithelial tissues and localized to hemidesmosomes, on the other hand, BPAG1n is expressed in neural tissues and muscles and has an actin binding domain at the NH(2)-terminal of BPAG1e. BPAG1 is also known as a gene responsible for Dystonia musculorum (dt) neurodegeneration syndrome of the mouse. Another plakin family protein MACF (microtubule actin cross-linking factor) has also an actin binding domain and the plakin domain at the NH(2)-terminal. However, in contrast to its high homology with BPAG1 at the NH(2)-terminal, the COOH-terminal structure of MACF, including a microtubule binding domain, resembles dystrophin rather than plakins. Here, we investigated RNAs and proteins expressed from the BPAG1 locus and suggest novel alternative splicing variants, which include one consisting of the COOH-terminal domain structure homologous to MACF. The results indicate that BPAG1 has three kinds of cytoskeletal binding domains and seems to play an important role in linking the different types of cytoskeletons.

    The Journal of biological chemistry 2002;277;8;6682-7

  • The hemidesmosomal protein bullous pemphigoid antigen 1 and the integrin beta 4 subunit bind to ERBIN. Molecular cloning of multiple alternative splice variants of ERBIN and analysis of their tissue expression.

    Favre B, Fontao L, Koster J, Shafaatian R, Jaunin F, Saurat JH, Sonnenberg A and Borradori L

    Department of Dermatology, University Medical School, 1211 Geneva 14, Switzerland.

    The bullous pemphigoid antigen 1 (eBPAG1) is a constituent of hemidesmosomes (HDs), cell-substrate adhesion complexes in stratified epithelia. Although its COOH terminus interacts with intermediate filaments, its NH(2) terminus is important for its recruitment into HDs. To identify proteins that interact with the NH(2) terminus of human eBPAG1, we performed a yeast two-hybrid screen, which uncovered a protein belonging to the LAP/LERP (for LRR and PDZ domain) protein family with 16 NH(2)-terminal leucine-rich repeats and a COOH-terminal PDZ domain. The gene for this LAP/LERP protein comprises at least 26 exons located on the long arm of chromosome 5. In most human tissues, several transcripts were detected differing in the coding region situated upstream of or within the PDZ domain. One of the encoded variants was found to correspond to the recently described protein ERBIN. In yeast and in vitro binding experiments, ERBIN was shown to interact not only with eBPAG1 but also with the COOH-terminal region of the cytoplasmic domain of the integrin beta4 subunit, another component of HDs. Antibodies raised against the COOH terminus showed that ERBIN is expressed in keratinocytes. In transfected epithelial cells the protein, however, was not localized in HDs but was either diffusely distributed over the cytoplasm or concentrated at the basolateral plasma membrane. Because ERBIN had been shown previously to interact with the transmembrane tyrosine kinase receptor Erb-B2, which in turn associates with the integrin beta4 subunit, we suggest that ERBIN provides a link between HD assembly and Erb-B2 receptor signaling.

    The Journal of biological chemistry 2001;276;35;32427-36

  • Clinical significance of enzyme-linked immunosorbent assay for the detection of circulating anti-BP180 autoantibodies in patients with bullous pemphigoid.

    Amo Y, Ohkawa T, Tatsuta M, Hamada Y, Fujimura T, Katsuoka K and Hashimoto T

    Department of Dermatology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, 228-8555, Kanagawa, Japan. amo@m.med.kitasato-u.ac.jp

    The NC16A domain of the 180-kDa bullous pemphigoid antigen (BP180) is the most immunogenic and, probably, pathogenic region in bullous pemphigoid (BP). In the present study, in order to determine whether serum level of circulating anti-BP180 autoantibodies is a valuable serum marker in BP, the immunoreactivity of sera against the NC16A domain of BP180 was measured using enzyme-linked immunosorbent assay (ELISA) in ten patients with BP. Serum levels of anti-BP180 autoantibodies correlated with the clinical course in BP patients, who received various therapeutic agents. The result suggests that this NC16A-ELISA is a useful method for evaluating the clinical course and efficacy of the therapy in patients with BP.

    Journal of dermatological science 2001;26;1;14-8

  • The tetraspan molecule CD151, a novel constituent of hemidesmosomes, associates with the integrin alpha6beta4 and may regulate the spatial organization of hemidesmosomes.

    Sterk LM, Geuijen CA, Oomen LC, Calafat J, Janssen H and Sonnenberg A

    Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.

    CD151 is a cell surface protein that belongs to the tetraspan superfamily. It associates with other tetraspan molecules and certain integrins to form large complexes at the cell surface. CD151 is expressed by a variety of epithelia and mesenchymal cells. We demonstrate here that in human skin CD151 is codistributed with alpha3beta1 and alpha6beta4 at the basolateral surface of basal keratinocytes. Immunoelectron microscopy showed that CD151 is concentrated in hemidesmosomes. By immunoprecipitation from transfected K562 cells, we established that CD151 associates with alpha3beta1 and alpha6beta4. In beta4-deficient pyloric atresia associated with junctional epidermolysis bullosa (PA-JEB) keratinocytes, CD151 and alpha3beta1 are clustered together at the basal cell surface in association with patches of laminin-5. Focal adhesions are present at the periphery of these clusters, connected with actin filaments, and they contain both CD151 and alpha3beta1. Transient transfection studies of PA-JEB cells with beta4 revealed that the integrin alpha6beta4 becomes incorporated into the alpha3beta1-CD151 clusters where it induces the formation of hemidesmosomes. As a result, the amount of alpha3beta1 in the clusters diminishes and the protein becomes restricted to the peripheral focal adhesions. Furthermore, CD151 becomes predominantly associated with alpha6beta4 in hemidesmosomes, whereas its codistribution with alpha3beta1 in focal adhesions becomes partial. The localization of alpha6beta4 in the pre-hemidesmosomal clusters is accompanied by a strong upregulation of CD151, which is at least partly due to increased cell surface expression. Using beta4 chimeras containing the extracellular and transmembrane domain of the IL-2 receptor and the cytoplasmic domain of beta4, we found that for recruitment of CD151 into hemidesmosomes, the beta4 subunit must be associated with alpha6, confirming that integrins associate with tetraspans via their alpha subunits. CD151 is the only tetraspan identified in hemidesmosomal structures. Others, such as CD9 and CD81, remain diffusely distributed at the cell surface. In conclusion, we show that CD151 is a major component of (pre)-hemidesmosomal structures and that its recruitment into hemidesmosomes is regulated by the integrin alpha6beta4. We suggest that CD151 plays a role in the formation and stability of hemidesmosomes by providing a framework for the spatial organization of the different hemidesmosomal components.

    The Journal of cell biology 2000;149;4;969-82

  • Human bronchial epithelial cells secrete laminin 5, express hemidesmosomal proteins, and assemble hemidesmosomes.

    Michelson PH, Tigue M and Jones JC

    Departments of Pediatrics, Northwestern University Medical School, Chicago, Iillinois, USA. pmichelson@nwu.edu

    Epithelial cells attach to the basement membrane through adhesive contacts between the basal cells of the epithelium and the proteins of the extracellular matrix (ECM). The hemidesmosome (HD) is a specialized cell-ECM contact, that mediates the attachment of the epithelial cell basal surface to the ECM. In bronchial epithelial cells, the protein components that constitute the HD have not been demonstrated. Using immunohistochemical techniques, we determined that normal human bronchial epithelial (NHBE) cells express the HD cell surface integrin alpha6beta4 and produce laminin 5, the ECM protein associated with HDs. Furthermore, expression of the HD-associated structural proteins, bullous pemphigoid antigens 1 (BPAG 1) and 2 (BPAG 2), was demonstrated in NHBE cells by immunofluorescence microscopy and immunoblot analyses. In addition, we confirmed the presence of laminin 5 in the basement membrane (BM) of bronchial epithelial biopsy specimens and of BP230, BP180, and the alpha6beta4 integrin heterodimer at the site of bronchial epithelial cell-ECM interaction in vivo. Finally, using electron microscopy, we were able to demonstrate intact HDs in a glutaraldehyde-fixed NHBE cell monolayer. These findings suggest that bronchial epithelium forms HDs and that the laminin 5-alpha6beta4 integrin interaction may be important in stabilizing epithelial cell adhesion to the BM in the lung.

    The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society 2000;48;4;535-44

  • The N terminus of the transmembrane protein BP180 interacts with the N-terminal domain of BP230, thereby mediating keratin cytoskeleton anchorage to the cell surface at the site of the hemidesmosome.

    Hopkinson SB and Jones JC

    Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, Illinois 60611, USA.

    In epidermal cells, the keratin cytoskeleton interacts with the elements in the basement membrane via a multimolecular junction called the hemidesmosome. A major component of the hemidesmosome plaque is the 230-kDa bullous pemphigoid autoantigen (BP230/BPAG1), which connects directly to the keratin-containing intermediate filaments of the cytoskeleton via its C terminus. A second bullous pemphigoid antigen of 180 kDa (BP180/BPAG2) is a type II transmembrane component of the hemidesmosome. Using yeast two-hybrid technology and recombinant proteins, we show that an N-terminal fragment of BP230 can bind directly to an N-terminal fragment of BP180. We have also explored the consequences of expression of the BP230 N terminus in 804G cells that assemble hemidesmosomes in vitro. Unexpectedly, this fragment disrupts the distribution of BP180 in transfected cells but has no apparent impact on the organization of endogenous BP230 and alpha6beta4 integrin. We propose that the BP230 N terminus competes with endogenous BP230 protein for BP180 binding and inhibits incorporation of BP180 into the cell surface at the site of the hemidesmosome. These data provide new insight into those interactions of the molecules of the hemidesmosome that are necessary for its function in integrating epithelial and connective tissue types.

    Funded by: NIGMS NIH HHS: R01 GM38470

    Molecular biology of the cell 2000;11;1;277-86

  • Integrators of the cytoskeleton that stabilize microtubules.

    Yang Y, Bauer C, Strasser G, Wollman R, Julien JP and Fuchs E

    Howard Hughes Medical Institute, Department of Molecular Genetics and Cell Biology, Chicago, Illinois 60637, USA.

    Sensory neurodegeneration occurs in mice defective in BPAG1, a gene encoding cytoskeletal linker proteins capable of anchoring neuronal intermediate filaments to actin cytoskeleton. While BPAG1 null mice fail to anchor neurofilaments (NFs), BPAG1/NF null mice still degenerate in the absence of NFs. We report a novel neural splice form that lacks the actin-binding domain and instead binds and stabilizes microtubules. This interaction is functionally important; in mice and in vitro, neurons lacking BPAG1 display short, disorganized, and unstable microtubules defective in axonal transport. Ironically, BPAG1 neural isoforms represent microtubule-associated proteins that when absent lead to devastating consequences. Moreover, BPAG1 can functionally account for the extraordinary stability of axonal microtubules necessary for transport over long distances. Its isoforms interconnect all three cytoskeletal networks, a feature apparently central to neuronal survival.

    Funded by: NIAMS NIH HHS: R01-AR27883

    Cell 1999;98;2;229-38

  • Prediction of the coding sequences of unidentified human genes. XI. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro.

    Nagase T, Ishikawa K, Suyama M, Kikuno R, Miyajima N, Tanaka A, Kotani H, Nomura N and Ohara O

    Kazusa DNA Research Institute, Kisarazu, Chiba, Japan.

    In our series of projects for accumulating sequence information on the coding sequences of unidentified human genes, we have newly determined the sequences of 100 cDNA clones from a set of size-fractionated human brain cDNA libraries, and predicted the coding sequences of the corresponding genes, named KIAA0711 to KIAA0810. These cDNA clones were selected according to their coding potentials of large proteins (50 kDa and more) in vitro. The average sizes of the inserts and corresponding open reading frames were 4.3 kb and 2.6 kb (869 amino acid residues), respectively. Sequence analyses against the public databases indicated that the predicted coding sequences of 78 genes were similar to those of known genes, 64% of which (50 genes) were categorized as proteins functionally related to cell signaling/communication, cell structure/motility and nucleic acid management. As additional information concerning genes characterized in this study, the chromosomal locations of the clones were determined by using human-rodent hybrid panels and the expression profiles among 10 human tissues were examined by reverse transcription-coupled polymerase chain reaction which was substantially improved by enzyme-linked immunosorbent assay.

    DNA research : an international journal for rapid publication of reports on genes and genomes 1998;5;5;277-86

  • Generation and analysis of 280,000 human expressed sequence tags.

    Hillier LD, Lennon G, Becker M, Bonaldo MF, Chiapelli B, Chissoe S, Dietrich N, DuBuque T, Favello A, Gish W, Hawkins M, Hultman M, Kucaba T, Lacy M, Le M, Le N, Mardis E, Moore B, Morris M, Parsons J, Prange C, Rifkin L, Rohlfing T, Schellenberg K, Bento Soares M, Tan F, Thierry-Meg J, Trevaskis E, Underwood K, Wohldman P, Waterston R, Wilson R and Marra M

    Genome Sequencing Center, Washington University School of Medicine, St. Louis, Missouri 63108, USA. lhillier@watson.wustl.edu

    We report the generation of 319,311 single-pass sequencing reactions (known as expressed sequence tags, or ESTs) obtained from the 5' and 3' ends of 194,031 human cDNA clones. Our goal has been to obtain tag sequences from many different genes and to deposit these in the publicly accessible Data Base for Expressed Sequence Tags. Highly efficient automatic screening of the data allows deposition of the annotated sequences without delay. Sequences have been generated from 26 oligo(dT) primed directionally cloned libraries, of which 18 were normalized. The libraries were constructed using mRNA isolated from 17 different tissues representing three developmental states. Comparisons of a subset of our data with nonredundant human mRNA and protein data bases show that the ESTs represent many known sequences and contain many that are novel. Analysis of protein families using Hidden Markov Models confirms this observation and supports the contention that although normalization reduces significantly the relative abundance of redundant cDNA clones, it does not result in the complete removal of members of gene families.

    Genome research 1996;6;9;807-28

  • Structural analysis of the predicted coiled-coil rod domain of the cytoplasmic bullous pemphigoid antigen (BPAG1). Empirical localization of the N-terminal globular domain-rod boundary.

    Tang HY, Chaffotte AF and Thacher SM

    Department of Medical Biochemistry and Genetics, Texas A & M College of Medicine, College Station, Texas 77843, USA.

    The bullous pemphigoid antigen BPAG1 is required for keratin filament linkage to the hemidesmosome, an adhesion complex in epithelial basal cells. BPAG1 structural organization is similar to the intermediate filament-associated proteins desmoplakin I (DPI) and plectin. All three proteins have predicted dumbbell-like structure with central alpha-helical coiled-coil rod and regions of N- and C-terminal homology. To characterize the size of the N-terminal globular domain in BPAG1, two polypeptides spanning possible boundaries with the coiled-coil rod domain of BPAG1 were expressed in Escherichia coli. BP-1 (Mr = 111,000), containing amino acids 663-1581 of BPAG1 (Sawamura, D., Li, K., Chu, M.-L., and Uitto, J. (1991) J. Biol. Chem. 266, 17784-17790), and BP-1A, with a 186 amino acid N-terminal deletion, were purified. BP-1 and BP-1A behave as highly asymmetric dimers in aqueous solution according to velocity sedimentation and gel filtration. Both have globular heads with rod-like tails of roughly equal length, 55-60 nm, upon rotary shadowing. BP-1A content of alpha-helix, determined by circular dichroism, is approximately 90%, consistent with alpha-helical coiled-coil formation in the rod-like tails. The estimated rod length, 383 +/- 57 amino acids (0.15 nm/amino acid), implies that globular folding in the BPAG1 N-terminal extends to the end of N-terminal homology with DPI and plectin. These findings support the existence of a common domain structure in the N-terminal regions of the BPAG1/DPI/plectin family.

    The Journal of biological chemistry 1996;271;16;9716-22

  • Cloning and characterization of the neural isoforms of human dystonin.

    Brown A, Dalpé G, Mathieu M and Kothary R

    Institut du cancer de Montréal, Centre de Recherche L.-C. Simard, Québec, Canada.

    Dystonia musculorum (dt) is a hereditary neurodegenerative disease in mice that leads to a sensory ataxia. We have identified and cloned a gene encoded at the dt locus. The product of the dt gene, dystonin, is a neural isoform of a hemidesmosomal protein bullous pemphigoid antigen 1 (bpag1). To investigate the potential role of dystonin in human neuropathies, we have cloned the neural-specific 5' exons of the human DT gene that together with the previously cloned BPAG1 sequences comprise human dystonin. The mouse and human dystonin genes demonstrate the same spectrum of alternatively spliced products, and the amino acid sequences of the neural-specific exons in the mouse and human genes are over 96% identical.

    Genomics 1995;29;3;777-80

  • Human homolog of a mouse sequence from the dystonia musculorum locus is on chromosome 6p12.

    Brown A, Lemieux N, Rossant J and Kothary R

    Institut du cancer de Montréal, Centre de Recherche L.-C. Simard, Quebec, Canada.

    Dystonia musculorum is a hereditary neurodegenerative disease in mice that affects sensory neurons. In an effort to clone the gene responsible for this disorder, we have assembled a genomic contig spanning 75 kb of the dystonia musculorum (dt) locus. Within this genomic contig, we have identified a small restriction fragment that shows evolutionary conservation to rat, hamster, rabbit, and human genomic DNA. Using this mouse sequence, we have cloned the conserved human genomic fragment. Sequence analysis of the mouse and human genomic fragments revealed that they share a sequence similarity of 82% over 175 bp. A panel of human/rodent somatic cell hybrids was used to map the human genomic sequence to Chromosome (Chr) 6, and high-resolution in situ hybridization (FISH) allowed it to be sublocalized to 6p12. The human homolog of the mouse Bpag1 gene, a gene tightly linked to the mouse dt gene, also maps to Chr 6. Thus, this comparative mapping reveals a new region of conserved synteny between the chromosomes of mouse and human. Mapping the human homolog of the mouse dt gene enables us to initiate linkage studies to identify neurodegenerative disorders that may be caused by mutations in this gene.

    Mammalian genome : official journal of the International Mammalian Genome Society 1994;5;7;434-7

  • Identification of a second protein product of the gene encoding a human epidermal autoantigen.

    Hopkinson SB and Jones JC

    Northwestern University Medical School, Chicago, IL 60611.

    A 230 kDa polypeptide component of the hemidesmosome, an epithelial-cell-connective-tissue attachment device, is thought to be involved in cytoskeleton-cell-surface anchorage. This 230 kDa polypeptide is recognized by bullous pemphigoid auto-antibodies and for this reason is generally termed the bullous pemphigoid antigen (BPA). We have identified two distinct mRNA products of the single BPA gene by RACE (rapid amplification of cDNA ends)/PCR techniques. The first of these mRNAs encodes the 230 kDa protein component of the hemidesmosome. A second mRNA lacks over 1800 bases that encode the C-terminus of the 230 kDa protein. We have raised antibodies against a peptide specific to the predicted protein product of this second mRNA. To our surprise this antibody recognizes a protein that migrates at 280 kDa on SDS/PAGE of extracts of a variety of human epidermal cell lines that also express the 230 kDa BPA. Moreover, we have confirmed the co-expression of the 230 and 280 kDa polypeptides in these cells by immunoblotting analyses using a monoclonal antibody preparation directed against a polypeptide encoded by sequence common to both mRNAs transcribed from the BPA gene. Intriguingly, in one non-epidermal tumour line (a pancreatic cell line termed FG), the 280 kDa polypeptide appears to be the only product of the BPA gene. Furthermore, in FG cells the 280 kDa protein is found in association with the intermediate filament cytoskeleton. We discuss our results in relation to control of BPA gene expression and with regard to potential functions of the domains of the protein products of the BPA gene.

    Funded by: NIGMS NIH HHS: GM38470

    The Biochemical journal 1994;300 ( Pt 3);851-7

  • Expression of laminin, type IV procollagen and 230 kDa bullous pemphigoid antigen genes by keratinocytes and fibroblasts in culture: application of the polymerase chain reaction for detection of small amounts of messenger RNA.

    Nomura K, Sugawara T, Sato T, Sawamura D, Hashimoto I, Sugita Y and Uitto J

    Department of Dermatology, Hirosaki University School of Medicine, Japan.

    In order to clarify whether keratinocytes and/or fibroblasts express genes encoding basement membrane zone macromolecules, we examined laminin, type IV collagen and 230 kDa bullous pemphigoid antigen (BPAG1) gene expression in keratinocytes and fibroblasts in culture. Northern transfer analysis revealed the presence of specific mRNA transcripts for alpha 1(IV) and alpha 2(IV) chains of type IV collagen as well as B1 and B2 chains of laminin in both fibroblast and keratinocyte RNA. Laminin A mRNA, however, was detected in fibroblasts but not in keratinocytes. In contrast, BPAG1 mRNA was detected in keratinocytes but not in fibroblasts using the same RNA preparations. A polymerase chain reaction (PCR) using laminin A and BPAG1-specific primers produced amplified DNAs with the predicted sizes in reverse-transcripted cDNA derived from keratinocyte and fibroblast RNA, respectively. These results provide evidence that normal human skin keratinocytes and fibroblasts express genes encoding laminin A, B1, B2, alpha 1(IV), and BPAG1 at a steady-state level. Moreover, the PCR for detecting small amounts of mRNA suggested that both keratinocytes and fibroblasts can be utilized for the analysis of DNA mutations in inherited skin diseases affecting the basement membrane zone, such as epidermolysis bullosa.

    Archives of dermatological research 1994;286;7;408-13

  • The human 230-kD bullous pemphigoid antigen gene (BPAG1). Exon-intron organization and identification of regulatory tissue specific elements in the promoter region.

    Tamai K, Sawamura D, Do HC, Tamai Y, Li K and Uitto J

    Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.

    The 230-kD bullous pemphigoid antigen (BPAG1), a hemidesmosomal protein, is encoded by a gene at the human chromosomal locus 6p11-12. We have elucidated the exon-intron organization of the entire human BPAG1 gene, including approximately 2.6 kb of 5'-flanking DNA. Seven overlapping genomic clones, spanning approximately 20 kb, contained the entire approximately 9 kb coding sequence of BPAG1 and consisted of 22 separate exons, which varied from 78 to 2,810 bp in size. The 5' flanking region of DNA, upstream from the ATG initiation codon for translation, was found to contain several putative transcriptional response elements. Most interestingly, two motifs potentially conferring keratinocyte specific expression to the gene were detected. The presence of such elements was suggested by approximately 20-fold higher expression of a promoter/chloramphenicol acetyl transferase (CAT) construct in normal human epidermal keratinocytes that express the endogenous gene, as compared to several non-expressing cell types. Transient transfections with 5'-deletion clones of the promoter/reporter gene (CAT) constructs identified a region containing a putative tissue specific element, KRE2, which also conferred tissue specificity to the expression of the truncated promoter downstream from this element, however, a mutated derivative of KRE2 was not functional. Detailed knowledge of the structure and regulation of the BPAG1 gene will aid in further elucidation of diseases affecting the cutaneous basement membrane zone.

    Funded by: NIAMS NIH HHS: 5-PO1-AR38923, T32-AR7561

    The Journal of clinical investigation 1993;92;2;814-22

  • Cloning of the 5' mRNA for the 230-kD bullous pemphigoid antigen by rapid amplification of cDNA ends.

    Elgart GW and Stanley JR

    Dermatology Branch, National Institutes of Health, Bethesda, Maryland 20892.

    The 230-kD bullous pemphigoid antigen (BPAG1), defined by autoantibodies in patient sera, is a hemidesmosomal plaque protein in the same gene family as the intracellular proteins desmoplakin I/II and plectin. We had previously isolated, from a lambda gt11 library, overlapping cDNA clones with 6921 bp of mRNA sequence for BPAG1. The coding sequence encoded by these clones included the 3' stop codon but not the 5' coding and non-coding region of the mRNA. To obtain these sequences we used the polymerase chain reaction (PCR) method called rapid amplification of cDNA ends (RACE). The PCR products were cloned into plasmids and sequenced. With five PCR primers we were able to obtain overlapping clones containing the 5' region of the mRNA. An upstream stop codon in frame with the rest of the coding sequence demonstrates that the full 5' coding sequence is obtained. Four different PCR products from two separate reactions had the same 5' end, suggesting that this 5' end is near, or at, the transcription start site. No alternatively spliced clones were found and no transmembrane site was predicted, confirming that BPAG1 is an intracellular hemidesmosomal plaque protein.

    The Journal of investigative dermatology 1993;101;2;244-6

  • Human bullous pemphigoid antigen (BPAG1). Amino acid sequences deduced from cloned cDNAs predict biologically important peptide segments and protein domains.

    Sawamura D, Li K, Chu ML and Uitto J

    Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.

    Bullous pemphigoid antigens are defined as the autoantigens in a blistering skin disease, bullous pemphigoid. One of them, a 230-kDa protein (BPAG1), is associated with hemidesmosomes, attachment complexes at the basal keratinocyte-lamina lucida interface within the dermal-epidermal basement membrane zone. The precise functions and cellular compartmentalization of BPAG1 are unknown. In this study, a human keratinocyte lambda gt11 cDNA library was screened for clones corresponding to BPAG1. The composite of overlapping cDNAs delineated 8,930 base pairs of nucleotide sequences that contained an open reading frame encoding 2,649 amino acids. Analysis of the deduced amino acid sequences predicted a putative signal peptide of 43 amino acids and the presence of a membrane-associated sequence of 17 amino acids. Several potential sites for N-glycosylation, as well as for protein kinase C or cAMP- and cGMP-dependent protein kinase-mediated phosphorylation were identified. Three peptide segments were predicted to be highly antigenic, potentially serving as epitopes for the formation of autoantibodies. Eight repeat segments of 38 residues each with a high degree of homology with sequences in desmoplakin I, a component of desmosomal cytoplasmic plaques, were detected in the carboxyl-terminal end of the molecule. In addition, the presence of three subdomains characterized by heptad repeats predicted an alpha-helical coiled coil dimer structure in the central portion of the protein. These data suggest that BPAG1 may be a membrane-associated protein that plays a role in the attachment of basal keratinocytes to the underlying basement membrane.

    Funded by: NIAMS NIH HHS: P01AR38923, T32AR7561

    The Journal of biological chemistry 1991;266;27;17784-90

  • Comparison of molecularly cloned bullous pemphigoid antigen to desmoplakin I confirms that they define a new family of cell adhesion junction plaque proteins.

    Tanaka T, Parry DA, Klaus-Kovtun V, Steinert PM and Stanley JR

    Dermatology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.

    Bullous pemphigoid is a subepidermal blistering disease in which patients have autoantibodies against the plaque of the hemidesmosome. Starting with a previously isolated 2-kilobase (kb) cDNA for bullous pemphigoid antigen (BPA), we used primer extension of keratinocyte mRNA to isolate overlapping cDNAs with a combined open reading frame of 6.3 kb, encoding most (243 kDa) of the BPA, but lacking the far amino terminus. Analysis of this amino acid sequence revealed a carboxyl-terminal domain containing two regions of 174 and 176 residues with high sequence identity. Most of the amino-terminal two-thirds of BPA is predicted to be in an alpha-helical conformation in which two chains would aggregate into a coiled-coil rod structure. BPA and desmoplakin I, a desmosome plaque protein, show remarkable sequence and structural homology. In its carboxyl-terminal domain, desmoplakin I also has 176 residue repeats with 40% sequence identity to those in BPA. The repeats in both molecules have a regular linear distribution of acidic and basic residues with a period of 9.5, the same as that found in the 1B segment of keratin filaments, suggesting a means of ionic interaction between keratin and these plaque proteins. Also, desmoplakin I, like BPA, is predicted to have a rod domain, which in both proteins has similar regular charge periodicities, suggesting a means of ionic self-aggregation. These findings extend those of Green et al. (Green, K. J., Parry, D. A. D., Steinert, P. S., Virata, L. A., Wagner, R. M., Angst, B. D., and Nilles, L. A. (1990) J. Biol. Chem. 265, 2603-2612) which show that BPA and desmoplakin I represent the first members of a new family of adhesion junction plaque proteins.

    The Journal of biological chemistry 1991;266;19;12555-9

  • Bullous pemphigoid antigen: cDNA cloning, cellular expression, and evidence for polymorphism of the human gene.

    Sawamura D, Li KH, Nomura K, Sugita Y, Christiano AM and Uitto J

    Department of Dermatology, Jefferson Medical College, Philadelphia, Pennsylvania.

    A human epidermal keratinocyte lambda gt11 recombinant cDNA library was screened with a 0.45-kb cDNA that was generated by polymerase chain reaction (PCR) amplification of a segment of human bullous pemphigoid (BP) antigen mRNA. The screen yielded five clones, the largest one, pcBPA-4, being 2.3 kb in size. The pcBPA-4 cDNA hybridized in Northern analyses with an approximately 9-kb mRNA from cultured keratinocytes, whereas no hybridization signal was detected with RNA from human skin fibroblast, fibrosarcoma HT-1080 cells, or amniotic epithelial WISH cell cultures. Nucleotide sequencing of pcBPA-4 revealed an open reading frame encoding a putative polypeptide of 447 amino acids. This polypeptide showed 88% homology with corresponding mouse BP antigen sequences, and a region of it was identical to a segment in previously published human BP antigen sequences. The 2.3-kb cDNA isolated here was different from a previously published human BP antigen cDNA, in that the open reading frame coded for 264 additional amino acids at the carboxyl end of the putative polypeptide. Known human BP antigen amino acid sequences, compared with mouse sequences, were predicted to be moderately divergent with a unit of evolutionary period (UEP) of 4.5 millions of years (MY). Southern hybridizations suggested that the BP antigen gene (BPAG1) is present as a single copy in the human genome. Southern analyses also revealed the presence of a StuI restriction fragment length polymorphism that can be used for linkage analyses to study the inheritance of a particular BPAG1 allele and a heritable cutaneous disorder affecting the basement membrane zone, such as epidermolysis bullosa.

    Funded by: NIAMS NIH HHS: AR-38923, T32AR-7561

    The Journal of investigative dermatology 1991;96;6;908-15

  • The hemidesmosomal plaque. I. Characterization of a major constituent protein as a differentiation marker for certain forms of epithelia.

    Owaribe K, Kartenbeck J, Stumpp S, Magin TM, Krieg T, Diaz LA and Franke WW

    Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg.

    To examine whether constituent proteins of hemidesmosomal structures can be used as markers for certain pathways of epithelial differentiation we have examined the occurrence of the major M- approximately 230,000 plaque protein, the "bullous pemphigoid" (BP) antigen. Several bovine, rat and human tissues and bovine cell culture lines were examined, using different human autoantibody preparations in immunocytochemistry and immunoblotting. We report that this protein, also unequivocally identified by cDNA cloning from expression libraries and DNA sequencing, occurs not only in different stratified epithelia but also, apparently always in hemidesmosomal structures, in urothelium of bladder and the complex epithelia of trachea, bronchus and several glands, notably myoepithelium-containing skin glands, the mammary gland and salivary glands. The protein is absent, however, in all single-layered epithelia and in several tissues reported to have subplasmalemmal densities structurally similar to hemidesmosomes, such as Purkinje fibers of heart, meninges and perineuria. A mammary-gland-derived epithelial cell line (BMGE + H) is particularly rich in hemidesmosomes. This has been used to study the endocytotic uptake of hemidesmosome-containing plasma membrane domains into cytoplasmic vesicles upon detachment of cell sheets during treatment with dispase, a proteolytic enzyme. We propose to use the Mr- approximately 230,000 plaque protein as a marker selective for certain subsets of epithelial cell types and epithelium-derived tumors in studies of fetal and tumor development, including differentiation diagnosis of carcinomas.

    Differentiation; research in biological diversity 1990;45;3;207-20

  • Bullous pemphigoid antigen (BPAG1): cDNA cloning and mapping of the gene to the short arm of human chromosome 6.

    Sawamura D, Nomura K, Sugita Y, Mattei MG, Chu ML, Knowlton R and Uitto J

    Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.

    Bullous pemphigoid antigen (BPAG1), an integral component of the cutaneous basement membrane zone, serves as autoantigen in a blistering disease, bullous pemphigoid. In this study, we have generated cDNAs corresponding to human BPAG1 sequences. Two cDNAs, a 0.45-kb PCR product synthesized with human keratinocyte RNA as template and a 2.2-kb cDNA isolated from human keratinocyte lambda gt11 library, were utilized for chromosomal in situ hybridizations to establish the genomic location of the BPAG1 gene. Metaphase chromosomes of phytohemagglutinin-stimulated human peripheral blood leukocytes were examined by hybridizations with 3H-labeled cDNAs, and the chromosomes were identified by R-banding (fluorochrome-photolysis-Giemsa method). The results indicated that the human BPAG1 gene is at locus 6p11-6p12. This conclusion was supported by hybridizations with a panel of human X rodent hybrid cell DNA, which indicated concordance with human chromosome 6. Because different genes encoding human basement membrane components have been mapped previously to chromosomes other than 6, the results further indicate that human basement membrane zone genes are widely dispersed within the human genome.

    Funded by: NIAMS NIH HHS: AR-38923, T32 AR-7561

    Genomics 1990;8;4;722-6

  • Definition of bullous pemphigoid antibody binding to intracellular and extracellular antigen associated with hemidesmosomes.

    Mutasim DF, Morrison LH, Takahashi Y, Labib RS, Skouge J, Diaz LA and Anhalt GJ

    Department of Dermatology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.

    Bullous pemphigoid (BP) antibodies are deposited predominantly in the lamina lucida in vivo; however, circulating BP antibodies bind in vitro to the cytoplasmic plaque of basal cell hemidesmosomes. We examined the ability of IgG in nine BP sera to bind to intracellular or extracellular antigen. On skin cryosections, indirect IF showed IgG bound to basement membrane zone (BMZ) and indirect ImmunoEM confirmed intracellular binding on the cytoplasmic plaque of hemidesmosomes. In contrast, when normal skin was exposed to BP serum in organ culture, direct IF showed fainter linear deposition of IgG along the BMZ, and direct ImmunoEM demonstrated extracellular IgG binding in the lamina lucida, predominantly beneath hemidesmosomes. Four of nine sera showed complement fixation on indirect IF samples (IgG bound to intracellular antigen) and three showed complement fixation on direct IF specimens (IgG bound to extracellular antigen). Three of the nine sera contained complement fixing antibodies detectable only in antibody populations specific for intracellular or extracellular antigen. Western immunoblots showed that five of nine sera recognized a 240-kD protein and four of nine recognized a 180-kD protein. There was no correlation between the presence (or absence) of either band and the detection of complement fixing antibodies specific for intracellular or extracellular antigen. BP autoantibodies bind both intracellular and extracellular antigen, and IgG binding exclusively to extracellular antigen that mimics the in vivo situation can be detected by using organ culture. Complement fixation may be restricted to antibodies specific for intracellular or extracellular antigen. These findings underscore the complexity of the autoantibody-antigen system in BP and have implications regarding the proposed pathogenicity of the autoantibodies.

    Funded by: NIAMS NIH HHS: R01-AR32081, R01-AR32490, R01-AR32599; ...

    The Journal of investigative dermatology 1989;92;2;225-30

  • Isolation of complementary DNA for bullous pemphigoid antigen by use of patients' autoantibodies.

    Stanley JR, Tanaka T, Mueller S, Klaus-Kovtun V and Roop D

    Dermatology Branch, National Cancer Institute, Bethesda, Maryland 20892.

    Autoantibodies from bullous pemphigoid (BP) patients define a 230-kD protein found in the basement membrane of stratified squamous epithelia. The purpose of this study was to isolate and characterize a cDNA clone with coding sequences for BP antigen. Poly(A+) RNA derived from total RNA of cultured keratinocytes was used, with oligo-dT priming, to construct a cDNA library in the lambda gt11 expression vector, which was screened by the immunoperoxidase method with one BP serum. One darkly stained clone, called here the BP clone, was further characterized. 9 of 9 BP sera, but none of 6 normal and 11 pemphigus sera, bound the plaques of this BP clone. Furthermore, BP IgG affinity purified on plaques of this clone, but not unrelated clones, bound the epidermal basement membrane by immunofluorescence and immunoprecipitated the 230-kD BP antigen from extracts of cultured keratinocytes. Eco RI digestion of the BP clone's cDNA insert demonstrated a 680- and 1,500-bp fragment. Northern blots of total keratinocyte RNA showed that complementary riboprobes transcribed from both fragments hybridized to a 9-kb RNA. Dideoxy DNA sequencing from the 5' end of the BP cDNA demonstrated a 1,992-bp open reading frame, encoding a peptide of 76 kD. This BP cDNA clone will be valuable for understanding the protein structure, expression, and gene organization of BP antigen.

    The Journal of clinical investigation 1988;82;6;1864-70

  • Bullous pemphigoid antigen localization suggests an intracellular association with hemidesmosomes.

    Westgate GE, Weaver AC and Couchman JR

    Autoantibodies to a normal component of stratified squamous epithelia, the bullous pemphigoid antigen (BPA), are synthesized in patients with the disease bullous pemphigoid. We have used these sera to study the distribution of BPA in vivo and in vitro. At low magnification, indirect immunofluorescent staining for BPA is linear at the basement membrane zone (BMZ) of skin and many other epithelial tissues. At higher magnification however, we observed a punctate staining pattern for BPA which was regular in appearance and suggested localization of BPA to discrete structures at the BMZ. Subsequent immunoelectron microscopy using both peroxidase and colloidal gold labeling techniques with patients' sera or IgG, revealed that BPA is associated with hemidesmosomes--putative adhesion structures at the BMZ, based on their similarity in ultrastructure to desmosomes. More specifically BPA was immunolocalized to the cytoplasmic face of hemidesmosomes and was not observed extracellularly in the basement membrane. In stratifying and nonstratifying cultures of rat keratinocytes, BPA is expressed intracellularly and not in the cell-derived matrix, unlike other known basement membrane components. These cells also synthesize BPA in vitro, and immunoprecipitation from metabolically labeled cultures revealed a 220 kD polypeptide under reducing conditions. From these observations we conclude (1) that BPA is a 220 kD polypeptide component either of or associated with hemidesmosomes, and (2) that it is localized intracellularly both in vivo and in vitro. We suggest that BPA is not normally a lamina lucida component, but that it may form part of a linkage between the cytoskeleton and the basement membrane.

    The Journal of investigative dermatology 1985;84;3;218-24

  • A pool of bullous pemphigoid antigen(s) is intracellular and associated with the basal cell cytoskeleton-hemidesmosome complex.

    Mutasim DF, Takahashi Y, Labib RS, Anhalt GJ, Patel HP and Diaz LA

    Bullous pemphigoid (BP) antibodies are known to react with an antigen of the basement membrane zone (BMZ) of squamous epithelia and produce, by the indirect immunofluorescence technique, linear fluorescence at the BMZ. Direct and indirect immunoelectron microscopy (IEM) have demonstrated BP antigen to be within the lamina lucida, in close association with the basal cell membrane. Trypsin-dissociated epidermal basal cells bind BP antibodies in a polar distribution, presumably because the BP antigen is restricted to the dermal pole of the basal cell membrane. In this study we have utilized newborn BALB/c mouse skin to obtain both dissociated basal cells (by trypsinization) and epidermal sheets (by dithiothreitol treatment). We show that viable basal cells, which are impermeable to IgG molecules, do not react with BP antibodies. When the basal cell plasma membrane is disrupted by cytospin centrifugation, air drying, freezing and thawing, or hypotonic lysis, or permeated by nonionic detergents (saponin), cells become reactive with BP antibodies. Basal cell cytoskeletons, prepared by sequential treatment with Triton X-100, deoxyribonuclease, and 2 M NaCl continue to react with BP antibodies. Similarly, viable epidermal sheets fail to bind BP antibodies. When epidermal sheets are treated with nonionic detergents, water, or freezing and thawing prior to incubation with BP antibodies, linear BMZ fluorescence is observed. IEM study of saponin-treated basal cells shows the immunoreactants to be localized on intracytoplasmic vacuoles which represent internalized hemidesmosomes. IEM of permeated epidermal sheets shows the immunoreactants as aggregates on the inner surface of the dermal pole of the basal cell membrane. These observations suggest that the BP antigen is intracellular and is in close association with the basal cell cytoskeleton and hemidesmosomes.

    Funded by: NIADDK NIH HHS: R01 AM 32081, R01 AM 32599, R23 AM 32079; ...

    The Journal of investigative dermatology 1985;84;1;47-53

Gene lists (6)

Gene List Source Species Name Description Gene count
L00000009 G2C Homo sapiens Human PSD Human orthologues of mouse PSD adapted from Collins et al (2006) 1080
L00000016 G2C Homo sapiens Human PSP Human orthologues of mouse PSP adapted from Collins et al (2006) 1121
L00000059 G2C Homo sapiens BAYES-COLLINS-HUMAN-PSD-CONSENSUS Human cortex PSD consensus 748
L00000061 G2C Homo sapiens BAYES-COLLINS-MOUSE-PSD-CONSENSUS Mouse cortex PSD consensus (ortho) 984
L00000069 G2C Homo sapiens BAYES-COLLINS-HUMAN-PSD-FULL Human cortex biopsy PSD full list 1461
L00000071 G2C Homo sapiens BAYES-COLLINS-MOUSE-PSD-FULL Mouse cortex PSD full list (ortho) 1556
© G2C 2014. The Genes to Cognition Programme received funding from The Wellcome Trust and the EU FP7 Framework Programmes:
EUROSPIN (FP7-HEALTH-241498), SynSys (FP7-HEALTH-242167) and GENCODYS (FP7-HEALTH-241995).

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