G2Cdb::Gene report

Gene id
Gene symbol
Homo sapiens
chaperonin containing TCP1, subunit 5 (epsilon)
G00000273 (Mus musculus)

Databases (7)

ENSG00000150753 (Ensembl human gene)
22948 (Entrez Gene)
600 (G2Cdb plasticity & disease)
CCT5 (GeneCards)
610150 (OMIM)
Marker Symbol
HGNC:1618 (HGNC)
Protein Sequence
P48643 (UniProt)

Synonyms (1)

  • KIAA0098

Literature (33)

Pubmed - other

  • Genes for hereditary sensory and autonomic neuropathies: a genotype-phenotype correlation.

    Rotthier A, Baets J, De Vriendt E, Jacobs A, Auer-Grumbach M, Lévy N, Bonello-Palot N, Kilic SS, Weis J, Nascimento A, Swinkels M, Kruyt MC, Jordanova A, De Jonghe P and Timmerman V

    Peripheral Neuropathy Group, VIB-Department of Molecular Genetics, University of Antwerp, Universiteitsplein 1, Antwerpen, Belgium.

    Hereditary sensory and autonomic neuropathies (HSAN) are clinically and genetically heterogeneous disorders characterized by axonal atrophy and degeneration, exclusively or predominantly affecting the sensory and autonomic neurons. So far, disease-associated mutations have been identified in seven genes: two genes for autosomal dominant (SPTLC1 and RAB7) and five genes for autosomal recessive forms of HSAN (WNK1/HSN2, NTRK1, NGFB, CCT5 and IKBKAP). We performed a systematic mutation screening of the coding sequences of six of these genes on a cohort of 100 familial and isolated patients diagnosed with HSAN. In addition, we screened the functional candidate gene NGFR (p75/NTR) encoding the nerve growth factor receptor. We identified disease-causing mutations in SPTLC1, RAB7, WNK1/HSN2 and NTRK1 in 19 patients, of which three mutations have not previously been reported. The phenotypes associated with mutations in NTRK1 and WNK1/HSN2 typically consisted of congenital insensitivity to pain and anhidrosis, and early-onset ulcero-mutilating sensory neuropathy, respectively. RAB7 mutations were only found in patients with a Charcot-Marie-Tooth type 2B (CMT2B) phenotype, an axonal sensory-motor neuropathy with pronounced ulcero-mutilations. In SPTLC1, we detected a novel mutation (S331F) corresponding to a previously unknown severe and early-onset HSAN phenotype. No mutations were found in NGFB, CCT5 and NGFR. Overall disease-associated mutations were found in 19% of the studied patient group, suggesting that additional genes are associated with HSAN. Our genotype-phenotype correlation study broadens the spectrum of HSAN and provides additional insights for molecular and clinical diagnosis.

    Brain : a journal of neurology 2009;132;Pt 10;2699-711

  • The CCT/TRiC chaperonin is required for maturation of sphingosine kinase 1.

    Zebol JR, Hewitt NM, Moretti PA, Lynn HE, Lake JA, Li P, Vadas MA, Wattenberg BW and Pitson SM

    Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Frome Road, Adelaide, SA 5000, Australia.

    Sphingosine kinase 1 (SK1) catalyses the generation of sphingosine 1-phosphate (S1P), a bioactive phospholipid that influences a diverse range of cellular processes, including proliferation, survival, adhesion, migration, morphogenesis and differentiation. SK1 is controlled by various mechanisms, including transcriptional regulation, and post-translational activation by phosphorylation and protein-protein interactions which can regulate both the activity and localisation of this enzyme. To gain a better understanding of the regulatory mechanisms controlling SK1 activity and function we performed a yeast two-hybrid screen to identify SK1-interacting proteins. Using this approach we identified that SK1 interacts with subunit 7 (eta) of cytosolic chaperonin CCT (chaperonin containing t-complex polypeptide, also called TRiC for TCP-1 ring complex), a hexadecameric chaperonin that binds unfolded polypeptides and mediates their folding and release in an ATP-dependent manner. Further analysis of the SK1-CCTeta interaction demonstrated that other CCT/TRiC subunits also associated with SK1 in HEK293T cell lysates in an ATP-sensitive manner, suggesting that the intact, functional, multimeric CCT/TRiC complex associated with SK1. Furthermore, pulse-chase studies indicated that CCT/TRiC binds specifically to newly translated SK1. Finally, depletion of functional CCT/TRiC through the use of RNA interference in HeLa cells or temperature sensitive CCT yeast mutants reduced cellular SK1 activity. Thus, combined this data suggests that SK1 is a CCT/TRiC substrate, and that this chaperonin facilitates folding of newly translated SK1 into its mature active form.

    The international journal of biochemistry & cell biology 2009;41;4;822-7

  • A PP2A phosphatase high density interaction network identifies a novel striatin-interacting phosphatase and kinase complex linked to the cerebral cavernous malformation 3 (CCM3) protein.

    Goudreault M, D'Ambrosio LM, Kean MJ, Mullin MJ, Larsen BG, Sanchez A, Chaudhry S, Chen GI, Sicheri F, Nesvizhskii AI, Aebersold R, Raught B and Gingras AC

    Samuel Lunenfeld Research Institute at Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada.

    The serine/threonine protein phosphatases are targeted to specific subcellular locations and substrates in part via interactions with a wide variety of regulatory proteins. Understanding these interactions is thus critical to understanding phosphatase function. Using an iterative affinity purification/mass spectrometry approach, we generated a high density interaction map surrounding the protein phosphatase 2A catalytic subunit. This approach recapitulated the assembly of the PP2A catalytic subunit into many different trimeric complexes but also revealed several new protein-protein interactions. Here we define a novel large multiprotein assembly, referred to as the striatin-interacting phosphatase and kinase (STRIPAK) complex. STRIPAK contains the PP2A catalytic (PP2Ac) and scaffolding (PP2A A) subunits, the striatins (PP2A regulatory B''' subunits), the striatin-associated protein Mob3, the novel proteins STRIP1 and STRIP2 (formerly FAM40A and FAM40B), the cerebral cavernous malformation 3 (CCM3) protein, and members of the germinal center kinase III family of Ste20 kinases. Although the function of the CCM3 protein is unknown, the CCM3 gene is mutated in familial cerebral cavernous malformations, a condition associated with seizures and strokes. Our proteomics survey indicates that a large portion of the CCM3 protein resides within the STRIPAK complex, opening the way for further studies of CCM3 biology. The STRIPAK assembly establishes mutually exclusive interactions with either the CTTNBP2 proteins (which interact with the cytoskeletal protein cortactin) or a second subcomplex consisting of the sarcolemmal membrane-associated protein (SLMAP) and the related coiled-coil proteins suppressor of IKKepsilon (SIKE) and FGFR1OP2. We have thus identified several novel PP2A-containing protein complexes, including a large assembly linking kinases and phosphatases to a gene mutated in human disease.

    Funded by: NHLBI NIH HHS: N01-HV-28179, N01HV28179

    Molecular & cellular proteomics : MCP 2009;8;1;157-71

  • PP4R4/KIAA1622 forms a novel stable cytosolic complex with phosphoprotein phosphatase 4.

    Chen GI, Tisayakorn S, Jorgensen C, D'Ambrosio LM, Goudreault M and Gingras AC

    Samuel Lunenfeld Research Institute at Mount Sinai Hospital, Toronto, Ontario M4M 2Y8, Canada.

    Protein serine/threonine phosphatase 4 (PP4c) is an essential polypeptide involved in critical cellular processes such as microtubule growth and organization, DNA damage checkpoint recovery, apoptosis, and tumor necrosis factor alpha signaling. Like other phosphatases of the PP2A family, PP4c interacts with regulatory proteins, which specify substrate targeting and intracellular localization. The identification of these regulatory proteins is, therefore, key to fully understanding the function of this enzyme class. Here, using a sensitive affinity purification/mass spectrometry approach, we identify a novel, stable cytosolic PP4c interacting partner, KIAA1622, which we have renamed PP4R4. PP4R4 displays weak sequence homology with the A (scaffolding) subunit of the PP2A holoenzyme and specifically associates with PP4c (and not with the related PP2Ac or PP6c phosphatases). The PP4c.PP4R4 interaction is disrupted by mutations analogous to those abrogating the association of PP2Ac with PP2A A subunit. However, unlike the PP2A A subunit, which plays a scaffolding role, PP4R4 does not bridge PP4c with previously characterized PP4 regulatory subunits. PP4c.PP4R4 complexes exhibit phosphatase activity toward a fluorogenic substrate and gammaH2AX, but this activity is lower than that associated with the PP4c.PP4R2.PP4R3 complex, which itself is less active than the free PP4c catalytic subunit. Our data demonstrate that PP4R4 forms a novel cytosolic complex with PP4c, independent from the complexes containing PP4R1, PP4R2.PP4R3, and alpha4, and that the regulatory subunits of PP4c have evolved different modes of interaction with the catalytic subunit.

    The Journal of biological chemistry 2008;283;43;29273-84

  • A genome-wide scan maps a novel high myopia locus to 5p15.

    Lam CY, Tam PO, Fan DS, Fan BJ, Wang DY, Lee CW, Pang CP and Lam DS

    Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.

    Purpose: This study was conducted to investigate the genetic component of three Chinese pedigrees originating from Hong Kong with autosomal dominant high myopia.

    Methods: A whole-genome scan was performed by using microsatellite markers spanning the whole genome with an average spacing of 10 cM. Regions containing markers that yielded LOD scores >1.0 were further analyzed by fine mapping with additional microsatellite markers. Fine-scale mapping of the linkage region was performed by genotyping a set of gene-based SNP markers on a cohort of 94 high myopia cases and 94 control subjects.

    Results: Two-point LOD scores >1 were observed at markers D5S630, D5S416, D7S510, D11S908, and D17S944. Additional microsatellite markers flanking D5S630 revealed a maximum two-point LOD score of 4.81 at D5S2505 at theta = 0.00. Haplotype analysis narrowed the linkage region to 5p15.33-p15.2 with a 17.45-cM interval. The coding sequences of five genes located within this region, IRX2, IRX1, POLS, CCT5, and CTNND2, were screened. No segregation of polymorphism with high myopia was found. Genotyping of 41 SNPs within this region in a Chinese cohort of 94 high myopia cases and 94 control subjects showed that the allele and genotype distributions of one SNP, rs370010, was different between cases and controls (genotype P = 0.01176, allele P = 0.00271 and trend P = 0.00375), but such association did not remain significant after false discovery rate (FDR) correction. This SNP is located within a hypothetical gene LOC442129.

    Conclusions: A novel autosomal dominant high myopia locus was mapped on chromosome 5p15.33-p15.2 with an interval of 17.45 cM.

    Investigative ophthalmology & visual science 2008;49;9;3768-78

  • Toward a confocal subcellular atlas of the human proteome.

    Barbe L, Lundberg E, Oksvold P, Stenius A, Lewin E, Björling E, Asplund A, Pontén F, Brismar H, Uhlén M and Andersson-Svahn H

    Department of Biotechnology, AlbaNova University Center, Royal Institute of Technology, SE-106 91 Stockholm, Sweden.

    Information on protein localization on the subcellular level is important to map and characterize the proteome and to better understand cellular functions of proteins. Here we report on a pilot study of 466 proteins in three human cell lines aimed to allow large scale confocal microscopy analysis using protein-specific antibodies. Approximately 3000 high resolution images were generated, and more than 80% of the analyzed proteins could be classified in one or multiple subcellular compartment(s). The localizations of the proteins showed, in many cases, good agreement with the Gene Ontology localization prediction model. This is the first large scale antibody-based study to localize proteins into subcellular compartments using antibodies and confocal microscopy. The results suggest that this approach might be a valuable tool in conjunction with predictive models for protein localization.

    Molecular & cellular proteomics : MCP 2008;7;3;499-508

  • Systematic analysis of the protein interaction network for the human transcription machinery reveals the identity of the 7SK capping enzyme.

    Jeronimo C, Forget D, Bouchard A, Li Q, Chua G, Poitras C, Thérien C, Bergeron D, Bourassa S, Greenblatt J, Chabot B, Poirier GG, Hughes TR, Blanchette M, Price DH and Coulombe B

    Laboratory of Gene Transcription and Proteomics Discovery Platform, Institut de Recherches Cliniques de Montréal, Montréal, QC, Canada.

    We have performed a survey of soluble human protein complexes containing components of the transcription and RNA processing machineries using protein affinity purification coupled to mass spectrometry. Thirty-two tagged polypeptides yielded a network of 805 high-confidence interactions. Remarkably, the network is significantly enriched in proteins that regulate the formation of protein complexes, including a number of previously uncharacterized proteins for which we have inferred functions. The RNA polymerase II (RNAP II)-associated proteins (RPAPs) are physically and functionally associated with RNAP II, forming an interface between the enzyme and chaperone/scaffolding proteins. BCDIN3 is the 7SK snRNA methylphosphate capping enzyme (MePCE) present in an snRNP complex containing both RNA processing and transcription factors, including the elongation factor P-TEFb. Our results define a high-density protein interaction network for the mammalian transcription machinery and uncover multiple regulatory factors that target the transcription machinery.

    Funded by: Canadian Institutes of Health Research: 14309-3, 82851-1

    Molecular cell 2007;27;2;262-74

  • Possible involvement of CCT5, RGS3, and YKT6 genes up-regulated in p53-mutated tumors in resistance to docetaxel in human breast cancers.

    Ooe A, Kato K and Noguchi S

    Department of Breast and Endocrine Surgery, Osaka University Graduate School of Medicine, 2-2-E10 Yamadaoka, Suita, Osaka 565-0871, Japan.

    Background: Present study was aimed to investigate the relationship of p53 mutation status with response to docetaxel in breast cancers. In addition, attempts were made to identify the genes differentially expressed between p53-wild and p53-mutated breast tumors and to study their relationship with response to docetaxel.

    Methods: Mutational analysis of p53 was done in 50 breast tumor samples obtained from primary breast cancer patients (n = 33) and locally recurrent breast cancer patients (n = 17) before docetaxel therapy. Response to docetaxel was evaluated clinically. Gene expression profiling (n = 2,412) was conducted by adapter-tagged competitive-PCR in 186 tumor samples, which were also analyzed in their p53 mutational status in order to identify the differentially expressed genes according to p53 mutation status and their relationship with response to docetaxel.

    Results: Response rate of p53-mutated tumors (44%) was lower than that of p53-wild tumors (62%) though there was no statistical significance (P = 0.23). Of 2412 genes, mRNA expression of 13 genes was significantly different between p53-wild and p53-mutated tumors. Of these 13 genes, mRNA expression of CCT5, RGS3, and YKT6 was significantly up-regulated in p53-mutated tumors and associated with a low response rate to docetaxel. Treatment of MCF-7 cells with siRNA specific for CCT5, RGS3, or YKT6 resulted in a significant enhancement of docetaxel-induced apoptosis.

    Conclusions: CCT5, RGS3, and YKT6 mRNA expressions, which are up-regulated in p53-mutated breast tumors, might be implicated in resistance to docetaxel and clinically useful in identifying the subset of breast cancer patients who may or may not benefit from docetaxel treatment.

    Breast cancer research and treatment 2007;101;3;305-15

  • Mutation in the epsilon subunit of the cytosolic chaperonin-containing t-complex peptide-1 (Cct5) gene causes autosomal recessive mutilating sensory neuropathy with spastic paraplegia.

    Bouhouche A, Benomar A, Bouslam N, Chkili T and Yahyaoui M

    Service de Neurologie et de Neurogénétique, Hôpital des Spécialités, Rabat, Morocco. abouhouche@hotmail.com

    Background: Mutilating sensory neuropathy with spastic paraplegia is a very rare disease with both autosomal dominant and recessive modes of inheritance. We previously mapped the locus of the autosomal recessive form to a 25 cM interval between markers D5S2048 and D5S648 on chromosome 5p. In this candidate interval, the Cct5 gene encoding the epsilon subunit of the cytosolic chaperonin-containing t-complex peptide-1 (CCT) was the most obvious candidate gene since mutation in the Cct4 gene encoding the CCT delta subunit has been reported to be associated with autosomal recessive mutilating sensory neuropathy in mutilated foot (mf) rat mutant.

    Methods: A consanguineous Moroccan family with four patients displaying mutilating sensory neuropathy associated with spastic paraplegia was investigated. To identify the disease causing gene, the 11 coding exons of the Cct5 gene were screened for mutations by direct sequencing in all family members including the four patients, parents, and six at risk relatives.

    Results: Sequence analysis of the Cct5 gene revealed a missense A492G mutation in exon 4 that results in the substitution of a highly conserved histidine for arginine amino acid 147. Interestingly, R147 was absent in 384 control matched chromosomes tested.

    Conclusion: This is the first disease causing mutation that has been identified in the human CCT subunit genes; the mf rat mutant could serve as an animal model for studying these chaperonopathies.

    Journal of medical genetics 2006;43;5;441-3

  • Transcriptomic and proteomic analyses of rhabdomyosarcoma cells reveal differential cellular gene expression in response to enterovirus 71 infection.

    Leong WF and Chow VT

    Human Genome Laboratory, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore 117597.

    Insights into the host antiviral strategies as well as viral disease manifestations can be achieved through the elucidation of host- and virus-mediated transcriptional responses. An oligo-based microarray was employed to analyse mRNAs from rhabdomyosarcoma cells infected with the MS/7423/87 strain of enterovirus 71 (EV71) at 20 h post infection. Using Acuity software and LOWESS normalization, 152 genes were found to be downregulated while 39 were upregulated by greater than twofold. Altered transcripts include those encoding components of cytoskeleton, protein translation and modification; cellular transport proteins; protein degradation mediators; cell death mediators; mitochondrial-related and metabolism proteins; cellular receptors and signal transducers. Changes in expression profiles of 15 representative genes were authenticated by real-time reverse transcription polymerase chain reaction (RT-PCR), which also compared the transcriptional responses of cells infected with EV71 strain 5865/Sin/000009 isolated from a fatal case during the Singapore outbreak in 2000. Western blot analyses of APOB, CLU, DCAMKL1 and ODC1 proteins correlated protein and transcript levels. Two-dimensional proteomic maps highlighted differences in expression of cellular proteins (CCT5, CFL1, ENO1, HSPB1, PSMA2 and STMN1) following EV71 infection. Expression of several apoptosis-associated genes was modified, coinciding with apoptosis attenuation observed in poliovirus infection. Interestingly, doublecortin and CaM kinase-like 1 (DCAMKL1) involved in brain development, was highly expressed during infection. Thus, microarray, real-time RT-PCR and proteomic analyses can elucidate the global view of the numerous and complex cellular responses that contribute towards EV71 pathogenesis.

    Cellular microbiology 2006;8;4;565-80

  • Proteomic analysis of SUMO4 substrates in HEK293 cells under serum starvation-induced stress.

    Guo D, Han J, Adam BL, Colburn NH, Wang MH, Dong Z, Eizirik DL, She JX and Wang CY

    Center for Biotechnology and Genomic Medicine, Medical College of Georgia, 1120 15th Street, CA4098, Augusta, GA 30912, USA.

    The substrates of SUMO4, a novel member for the SUMO gene family, were characterized in HEK293 cells cultured under serum starvation by proteomic analysis. We identified 90 SUMO4 substrates including anti-stress proteins such as antioxidant enzymes and molecular chaperones or co-chaperones. The substrates also include proteins involved in the regulation of DNA repair and synthesis, RNA processing, protein degradation, and glucose metabolism. Several SUMO4-associated transcription factors were characterized by Western blot analyses. AP-1 was selected for in vitro conjugation assays to confirm SUMO4 sumoylation of these transcription factors. Further functional analyses of the transcription factors suggested that SUMO4 sumoylation represses AP-1 and AP-2alpha transcriptional activity, but enhances GR DNA binding capacity. These results demonstrate that SUMO4 sumoylation may play an important role in the regulation of intracellular stress.

    Biochemical and biophysical research communications 2005;337;4;1308-18

  • A novel, evolutionarily conserved protein phosphatase complex involved in cisplatin sensitivity.

    Gingras AC, Caballero M, Zarske M, Sanchez A, Hazbun TR, Fields S, Sonenberg N, Hafen E, Raught B and Aebersold R

    Institute for Systems Biology, Seattle, Washington 98103, USA. agingras@systemsbiology.org

    Using a combination of tandem affinity purification tagging and mass spectrometry, we characterized a novel, evolutionarily conserved protein phosphatase 4 (PP4)-containing complex (PP4cs, protein phosphatase 4, cisplatin-sensitive complex) that plays a critical role in the eukaryotic DNA damage response. PP4cs is comprised of the catalytic subunit PP4C; a known regulatory subunit, PP4R2; and a novel protein that we termed PP4R3. The Saccharomyces cerevisiae PP4R3 ortholog Psy2 was identified previously in a screen for sensitivity to the DNA-damaging agent and anticancer drug cisplatin. We demonstrated that deletion of any of the PP4cs complex orthologs in S. cerevisiae elicited cisplatin hypersensitivity. Furthermore human PP4R3 complemented the yeast psy2 deletion, and Drosophila melanogaster lacking functional PP4R3 (flfl) exhibited cisplatin hypersensitivity, suggesting a highly conserved role for PP4cs in DNA damage repair. Finally we found that PP4R3 may target PP4cs to the DNA damage repair machinery at least in part via an interaction with Rad53 (CHK2).

    Funded by: NCRR NIH HHS: P41 RR11823; NHLBI NIH HHS: N01-HV-28179

    Molecular & cellular proteomics : MCP 2005;4;11;1725-40

  • Towards a proteome-scale map of the human protein-protein interaction network.

    Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, Berriz GF, Gibbons FD, Dreze M, Ayivi-Guedehoussou N, Klitgord N, Simon C, Boxem M, Milstein S, Rosenberg J, Goldberg DS, Zhang LV, Wong SL, Franklin G, Li S, Albala JS, Lim J, Fraughton C, Llamosas E, Cevik S, Bex C, Lamesch P, Sikorski RS, Vandenhaute J, Zoghbi HY, Smolyar A, Bosak S, Sequerra R, Doucette-Stamm L, Cusick ME, Hill DE, Roth FP and Vidal M

    Center for Cancer Systems Biology and Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, Massachusetts 02115, USA.

    Systematic mapping of protein-protein interactions, or 'interactome' mapping, was initiated in model organisms, starting with defined biological processes and then expanding to the scale of the proteome. Although far from complete, such maps have revealed global topological and dynamic features of interactome networks that relate to known biological properties, suggesting that a human interactome map will provide insight into development and disease mechanisms at a systems level. Here we describe an initial version of a proteome-scale map of human binary protein-protein interactions. Using a stringent, high-throughput yeast two-hybrid system, we tested pairwise interactions among the products of approximately 8,100 currently available Gateway-cloned open reading frames and detected approximately 2,800 interactions. This data set, called CCSB-HI1, has a verification rate of approximately 78% as revealed by an independent co-affinity purification assay, and correlates significantly with other biological attributes. The CCSB-HI1 data set increases by approximately 70% the set of available binary interactions within the tested space and reveals more than 300 new connections to over 100 disease-associated proteins. This work represents an important step towards a systematic and comprehensive human interactome project.

    Funded by: NCI NIH HHS: R33 CA132073; NHGRI NIH HHS: P50 HG004233, R01 HG001715, RC4 HG006066, U01 HG001715; NHLBI NIH HHS: U01 HL098166

    Nature 2005;437;7062;1173-8

  • A human protein-protein interaction network: a resource for annotating the proteome.

    Stelzl U, Worm U, Lalowski M, Haenig C, Brembeck FH, Goehler H, Stroedicke M, Zenkner M, Schoenherr A, Koeppen S, Timm J, Mintzlaff S, Abraham C, Bock N, Kietzmann S, Goedde A, Toksöz E, Droege A, Krobitsch S, Korn B, Birchmeier W, Lehrach H and Wanker EE

    Max Delbrueck Center for Molecular Medicine, 13092 Berlin-Buch, Germany.

    Protein-protein interaction maps provide a valuable framework for a better understanding of the functional organization of the proteome. To detect interacting pairs of human proteins systematically, a protein matrix of 4456 baits and 5632 preys was screened by automated yeast two-hybrid (Y2H) interaction mating. We identified 3186 mostly novel interactions among 1705 proteins, resulting in a large, highly connected network. Independent pull-down and co-immunoprecipitation assays validated the overall quality of the Y2H interactions. Using topological and GO criteria, a scoring system was developed to define 911 high-confidence interactions among 401 proteins. Furthermore, the network was searched for interactions linking uncharacterized gene products and human disease proteins to regulatory cellular pathways. Two novel Axin-1 interactions were validated experimentally, characterizing ANP32A and CRMP1 as modulators of Wnt signaling. Systematic human protein interaction screens can lead to a more comprehensive understanding of protein function and cellular processes.

    Cell 2005;122;6;957-68

  • Phosducin-like protein acts as a molecular chaperone for G protein betagamma dimer assembly.

    Lukov GL, Hu T, McLaughlin JN, Hamm HE and Willardson BM

    Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.

    Phosducin-like protein (PhLP) is a widely expressed binding partner of the G protein betagamma subunit dimer (Gbetagamma). However, its physiological role is poorly understood. To investigate PhLP function, its cellular expression was blocked using RNA interference, resulting in inhibition of Gbetagamma expression and G protein signaling. This inhibition was caused by an inability of nascent Gbetagamma to form dimers. Phosphorylation of PhLP at serines 18-20 by protein kinase CK2 was required for Gbetagamma formation, while a high-affinity interaction of PhLP with the cytosolic chaperonin complex appeared unnecessary. PhLP bound nascent Gbeta in the absence of Ggamma, and S18-20 phosphorylation was required for Ggamma to associate with the PhLP-Gbeta complex. Once Ggamma bound, PhLP was released. These results suggest a mechanism for Gbetagamma assembly in which PhLP stabilizes the nascent Gbeta polypeptide until Ggamma can associate, resulting in membrane binding of Gbetagamma and release of PhLP to catalyze another round of assembly.

    Funded by: NEI NIH HHS: EY12287, R01 EY012287

    The EMBO journal 2005;24;11;1965-75

  • 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

  • A protein interaction framework for human mRNA degradation.

    Lehner B and Sanderson CM

    MRC Rosalind Franklin Centre for Genomics Research, Hinxton, Cambridge CB10 1SB, United Kingdom.

    The degradation of mRNA is an important regulatory step in the control of gene expression. However, mammalian RNA decay pathways remain poorly characterized. To provide a framework for studying mammalian RNA decay, a two-hybrid protein interaction map was generated using 54 constructs from 38 human proteins predicted to function in mRNA decay. The results provide evidence for interactions between many different proteins required for mRNA decay. Of particular interest are interactions between the poly(A) ribonuclease and the exosome and between the Lsm complex, decapping factors, and 5'-->3' exonucleases. Moreover, multiple interactions connect 5'-->3' and 3'-->5' decay proteins to each other and to nonsense-mediated decay factors, providing the opportunity for coordination between decay pathways. The interaction network also predicts the internal organization of the exosome and Lsm complexes. Additional interactions connect mRNA decay factors to many novel proteins and to proteins required for other steps in gene expression. These results provide an experimental insight into the organization of proteins required for mRNA decay and their coupling to other cellular processes, and the physiological relevance of many of these interactions are supported by their evolutionary conservation. The interactions also provide a wealth of hypotheses to guide future research on mRNA degradation and demonstrate the power of exhaustive protein interaction mapping in aiding understanding of uncharacterized protein complexes and pathways.

    Genome research 2004;14;7;1315-23

  • 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

  • A product of the human gene adjacent to parkin is a component of Lewy bodies and suppresses Pael receptor-induced cell death.

    Imai Y, Soda M, Murakami T, Shoji M, Abe K and Takahashi R

    Laboratory for Motor System Neurodegeneration, RIKEN Brain Science Institute, Saitama 351-0198, Japan.

    Parkin, a RING-type ubiquitin ligase, is the product of the gene responsible for autosomal recessive juvenile parkinsonism. A reverse strand gene located upstream of the parkin gene in the human genome has been identified. The gene product, termed Glup/PACRG, forms a large molecular chaperone complex containing heat shock proteins 70 and 90 and chaperonin components. Glup suppressed cell death induced by accumulation of unfolded Pael receptor (Pael-R), a substrate of Parkin. On the other hand, Glup facilitated the formation of inclusions consisting of Pael-R, molecular chaperones, protein degradation molecules, and Glup itself, when proteasome is inhibited. Glup knockdown attenuated the formation of Pael-R inclusions, which resulted in the promotion of cell death with extensive vacuolization. Moreover, Glup turned out to be a component of Lewy bodies in Parkinson's disease cases. These data suggest that Glup may play an important role in the formation of Lewy bodies and protection of dopaminergic neurons against Parkinson's disease.

    The Journal of biological chemistry 2003;278;51;51901-10

  • Assembly of the SMRT-histone deacetylase 3 repression complex requires the TCP-1 ring complex.

    Guenther MG, Yu J, Kao GD, Yen TJ and Lazar MA

    Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.

    The acetylation of histone tails is a primary determinant of gene activity. Histone deacetylase 3 (HDAC3) requires the nuclear receptor corepressor SMRT for HDAC enzyme activity. Here we report that HDAC3 interacts with SMRT only after priming by cellular chaperones including the TCP-1 ring complex (TRiC), which is required for proper folding of HDAC3 in an ATP-dependent process. SMRT displaces TRiC from HDAC3, yielding an active HDAC enzyme. The SMRT-HDAC3 repression complex thus joins the VHL-elongin BC tumor suppression complex and the cyclin E-Cdk2 cell cycle regulation complex as critical cellular machines requiring TRiC for proper assembly and function. The strict control of HDAC3 activity underscores the cellular imperative that histone deacetylation occur only in targeted regions of the genome.

    Funded by: NCI NIH HHS: CA06927, P30 CA006927; NIDDK NIH HHS: DK43806, DK45586, R01 DK045586, R37 DK043806

    Genes & development 2002;16;24;3130-5

  • Identification of differentially expressed genes in classical and atypical multidrug-resistant gastric carcinoma cells.

    Ludwig A, Dietel M and Lage H

    Institute of Pathology, Charité Campus Mitte, Humboldt University Berlin, Schumannstr. 20/21, D-10117 Berlin, Germany.

    The phenomenon of multidrug resistance (MDR) in human cancers is the major cause of failure of chemotherapy. To better understand the molecular events associated with the development of different types of MDR, a classical MDR P-glycoprotein expressing gastric carcinoma cell line and an atypical MDR P-glycoprotein-negative variant were analyzed by cDNA array hybridization. Of 588 cDNAs spotted on the array, a total of 9 genes showed differences in mRNA expressions. An enhanced expression level of 3 genes could be detected in both different MDR models (HLH, IR21, CCT5, Tx P-1), 4 genes were overexpressed solely in classical MDR cells (Hsp27, Rcl, aldehyde dehydrogenase 1, vimentin), whereas the expression of one gene was increased in atypical MDR cells (ProTa). Furthermore, the mRNA expressions of 3 genes were down-regulated in atypical MDR cells (Hsp27, vimentin, JNK2), whereas a decrease in mRNA expression in classical MDR cells could be determined for none of them. These differences were confirmed by a semiquantitative RT-PCR approach. Further characterization of these factors may provide more insight into the biology and development of different types of MDR in human gastric carcinomas. Moreover, these genes may be potential candidate factors for the diagnostics and/or prognosis of clinical drug resistance.

    Anticancer research 2002;22;6A;3213-21

  • Cytosolic chaperonin-containing t-complex polypeptide 1 changes the content of a particular subunit species concomitant with substrate binding and folding activities during the cell cycle.

    Yokota S, Yanagi H, Yura T and Kubota H

    HSP Research Institute, Kyoto Research Park, Shimogyo-ku, Kyoto, Japan.

    The chaperonin-containing t-complex polypeptide 1 (CCT) is a cytosolic molecular chaperone composed of eight subunits that assists in the folding of actin, tubulin and other cytosolic proteins. We show here that the content of particular subunits of CCT within mammalian cells decreases concomitantly with the reduction of chaperone activity during cell cycle arrest at M phase. CCT recovers chaperone activity upon resumption of these subunits after release from M phase arrest or during arrest at S phase. The levels of alpha, delta and zeta-1 subunits decreased more rapidly than the other subunits during M phase arrest by colcemid treatment and recovered after release from the arrest. Gel filtration chromatography or native (nondenaturing) PAGE analysis followed by immunoblotting indicated that the alpha and delta subunit content in the 700- to 900-kDa CCT complex was appreciably lower in the M phase cells than in asynchronous cells. In vivo, the CCT complex of M-phase-arrested cells was found to bind lower amounts of tubulin than that of asynchronous cells. In vitro, the CCT complex of M phase-arrested cells was less active in binding and folding denatured actin than that of asynchronous cells. On the other hand, the CCT complex of asynchronous cells (a mixture of various phases of cell cycle) exhibited lower alpha and delta subunit content and lower chaperone activity than that of S-phase-arrested cells obtained by excess thymidine treatment. In addition, turnover (synthesis and degradation) rates of the alpha and delta subunits in vivo were more rapid than those of most other subunits. These results suggest that the content of alpha and delta subunits of CCT reduces from the complete active complex in S phase cells to incomplete inactive complex in M phase cells.

    European journal of biochemistry 2001;268;17;4664-73

  • Analysis of the interaction between the eukaryotic chaperonin CCT and its substrates actin and tubulin.

    Llorca O, Martín-Benito J, Gómez-Puertas P, Ritco-Vonsovici M, Willison KR, Carrascosa JL and Valpuesta JM

    Centro Nacional de Biotecnología, C.S.I.C., Campus Universidad Autónoma de Madrid, 28049, Spain.

    Two mechanisms have thus far been characterized for the assistance by chaperonins of the folding of other proteins. The first and best described is that of the prokaryotic chaperonin GroEL, which interacts with a large spectrum of proteins. GroEL uses a nonspecific mechanism by which any conformation of practically any unfolded polypeptide interacts with it through exposed, hydrophobic residues. ATP binding liberates the substrate in the GroEL cavity where it is given a chance to fold. A second mechanism has been described for the eukaryotic chaperonin CCT, which interacts mainly with the cytoskeletal proteins actin and tubulin. Cryoelectron microscopy and biochemical studies have revealed that both of these proteins interact with CCT in quasi-native, defined conformations. Here we have performed a detailed study of the docking of the actin and tubulin molecules extracted from their corresponding CCT:substrate complexes obtained from cryoelectron microscopy and image processing to localize certain regions in actin and tubulin that are involved in the interaction with CCT. These regions of actin and tubulin, which are not present in their prokaryotic counterparts FtsA and FtsZ, are involved in the polymerization of the two cytoskeletal proteins. These findings suggest coevolution of CCT with actin and tubulin in order to counteract the folding problems associated with the generation in these two cytoskeletal protein families of new domains involved in their polymerization.

    Journal of structural biology 2001;135;2;205-18

  • Point mutations in a hinge linking the small and large domains of beta-actin result in trapped folding intermediates bound to cytosolic chaperonin CCT.

    McCormack EA, Llorca O, Carrascosa JL, Valpuesta JM and Willison KR

    Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, United Kingdom.

    The 30-A cryo-EM-derived structure of apo-CCT-alpha-actin shows actin opened up across its nucleotide-binding cleft and binding to either of two CCT subunit pairs, CCTbeta-CCTdelta or CCTepsilon-CCTdelta, in a similar 1:4 arrangement. The two main duplicated domains of native actin are linked twice, topologically, by the connecting residues, Q137-S145 and P333-S338, and are tightly held together by hydrogen bonding with bound adenine nucleotide. We carried out a mutational screen to find residues in actin that might be involved in the huge rotations observed in the CCT-bound folding intermediate. When two evolutionarily highly conserved glycine residues of beta-actin, G146 and G150, were changed to proline, both mutant actin proteins were poorly processed by CCT in in vitro translation assays; they become arrested on CCT. A three-dimensional reconstruction of the substrate-bound ring of the apo-CCT-beta-actin complex shows that beta-actin G150P is not able to bind across the chaperonin cavity to interact with the CCTdelta subunit. beta-actin G150P seems tightly packed and apparently bound only to the CCTbeta and CCTepsilon subunits, which further indicates that these CCT subunits drive the interaction between CCT and actin. Hinge opening seems to be critical for actin folding, and we suggest that residues G146 and G150 are important components of the hinge around which the rigid subdomains, presumably already present in early actin folding intermediates, rotate during CCT-assisted folding.

    Journal of structural biology 2001;135;2;198-204

  • Differential expression of molecular chaperones in brain of patients with Down syndrome.

    Yoo BC, Vlkolinsky R, Engidawork E, Cairns N, Fountoulakis M and Lubec G

    Department of Pediatrics, University of Vienna, Austria.

    Heat shock proteins (HSPs) in their molecular capacity as chaperones have been reported to regulate the apoptotic pathway and also play a critical role in protein conformational diseases such as Alzheimer's disease (AD). As all Down syndrome (DS) brains display AD-like neuropathology, neuronal loss in DS was shown to be mediated by apoptosis. We decided to investigate the expression patterns of HSPs in seven brain regions of adults with DS using two-dimensional polyacrylamide gel electrophoresis (2-DE). Following 2-DE, approximately 120 protein spots were successfully identified by matrix-assisted laser desorption/ionization--mass spectrometry (MALDI-MS) followed by quantification of the identified proteins. We unambiguously identified and quantified nine different chaperone proteins. Accordingly, all but three chaperone proteins did exhibit a significant change in expression. HSP 70 RY, heat shock cognate (HSC) 71 and glucose-regulated protein (GRP) 75 showed a significant decrease (P < 0.05) in DS temporal cortex whereas HSP 70.1 and GRP 78 were significantly increased (P<0.05) in cerebellum. Whilst T-complex 1 (TCP-1) epsilon subunit showed a significant decrease (P< 0.05) in parietal cortex, a similar extent of increase (P<0.05) as that observed in cerebellum was obtained in parietal levels of GRP 78. Alpha-crystallin B, HSP 60 and GRP 94 did not show any detectable changes in expression patterns. This report presents the first approach to quantify nine different chaperones simultaneously at the protein level in different brain regions and provides evidence for aberrant chaperone expression patterns in DS. The relevance of this aberrant expression patterns are discussed in relation to the biochemical and neuropathological abnormalities in DS brain.

    Electrophoresis 2001;22;6;1233-41

  • Deranged expression of molecular chaperones in brains of patients with Alzheimer's disease.

    Yoo BC, Kim SH, Cairns N, Fountoulakis M and Lubec G

    Department of Pediatrics, University of Vienna, Vienna, Austria.

    Alzheimer's disease (AD) is one of the disorders caused by protein conformational changes and recent studies have shown that several chaperone proteins are involved in this process. As information of chaperone expression in AD brain is limited, we aimed to study the expressional pattern of chaperones in several brain regions, as this may be essential to understand how folding defects can lead to disease. We studied the concomitant expressional patterns of molecular chaperones in seven brain regions of adults with AD using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-associated laser desorption ionization mass spectroscopy (MALDI-MS). We unambiguously identified and quantified nine different chaperone proteins. Six chaperone proteins, heat shock protein 60 (HSP 60), HSP 70 RY, heat shock cognate (HSC) 71, alpha crystallin B chain, glucose regulated protein (GRP) 75, and GRP 94 showed aberrant expressional patterns depending on brain region. HSP 70.1, GRP 78 and T-complex 1 (TCP-1) epsilon subunit did not show any significant expressional change. These findings are compatible with neuropathological and biochemical abnormalities in AD brain and this report presents the first approach to quantify nine different chaperones simultaneously at the protein level in individual AD brain regions providing evidence for the relevance of aberrant chaperone expression to AD neuropathology.

    Biochemical and biophysical research communications 2001;280;1;249-58

  • Insertional mutation of the murine kisimo locus caused a defect in spermatogenesis.

    Yanaka N, Kobayashi K, Wakimoto K, Yamada E, Imahie H, Imai Y and Mori C

    Discovery Research Laboratory, Safety Research Laboratory, and Department of Advanced Medical Research, Tanabe Seiyaku Co., Ltd., 16-89, Kashima 3-chome, Yodogawa-ku, Osaka 532-8505, Japan. n-yanaka@tanabe.co.jp

    Spermatogenesis is a developmental process that occurs in several phases and is regulated by a large number of gene products. An insertional transgenic mouse mutant (termed kisimo mouse) has been isolated that results in abnormal germ-cell development, showing abnormal elongated spermatids in the lumina of seminiferous tubules. We cloned the disrupted locus of kisimo and identified a novel testis-specific gene, THEG, which is specifically expressed in spermatids and was disrupted in the transgenic mouse. The yeast two-hybrid screening method revealed that THEG protein strongly interacts with chaperonin containing t-complex polypeptide-1epsilon, suggesting that THEG protein functions as a regulatory factor in protein assembly. Our findings indicate that the kisimo locus is essential for the maintenance of spermiogenesis and that a gene expression disorder may be involved in male infertility.

    The Journal of biological chemistry 2000;275;20;14791-4

  • SIAH-1 promotes apoptosis and tumor suppression through a network involving the regulation of protein folding, unfolding, and trafficking: identification of common effectors with p53 and p21(Waf1).

    Roperch JP, Lethrone F, Prieur S, Piouffre L, Israeli D, Tuynder M, Nemani M, Pasturaud P, Gendron MC, Dausset J, Oren M, Amson RB and Telerman A

    Fondation Jean Dausset-CEPH (Human Polymorphism Study Center), 27 rue Juliette Dodu, 75010 Paris, France.

    We have previously described biological model systems for studying tumor suppression in which, by using H-1 parvovirus as a selective agent, cells with a strongly suppressed malignant phenotype (KS or US) were derived from malignant cell lines (K562 or U937). By using cDNA display on the K562/KS cells, 15 cDNAs were now isolated, corresponding to genes differentially regulated in tumor suppression. Of these, TSAP9 corresponds to a TCP-1 chaperonin, TSAP13 to a regulatory proteasome subunit, and TSAP21 to syntaxin 11, a vesicular trafficking molecule. The 15 cDNAs were used as a molecular fingerprint in different tumor-suppression models. We found that a similar pattern of differential regulation is shared by activation of p53, p21(Waf1), and the human homologue of Drosophila seven in absentia, SIAH-1. Because SIAH-1 is differentially expressed in the various models, we characterized it at the protein and functional levels. The 32-kDa, mainly nuclear protein encoded by SIAH-1, can induce apoptosis and promote tumor suppression. These results suggest the existence of a common mechanism of tumor suppression and apoptosis shared by p53, p21(Waf1), and SIAH-1 and involving regulation of the cellular machinery responsible for protein folding, unfolding, and trafficking.

    Proceedings of the National Academy of Sciences of the United States of America 1999;96;14;8070-3

  • Elucidation of the subunit orientation in CCT (chaperonin containing TCP1) from the subunit composition of CCT micro-complexes.

    Liou AK and Willison KR

    CRC Centre for Cell and Molecular Biology, Institute of Cancer Research, Chester Beatty Laboratories, London, UK.

    A collection of chaperonin containing TCP1 (CCT) micro-complexes that are comprised of subsets of the constitutively expressed CCT subunits have been identified. These CCT micro-complexes have mol. wts ranging from 120 to 250 kDa and are present in cells at lower abundance (<5%) as compared with intact CCT. Biochemical characterization of these microcomplexes has shown that several are comprised of two different types of CCT subunit. Furthermore, it was observed that each subunit associates with only one or two other different types of subunit, suggesting that each subunit has fixed partners. This observation, together with CCT gene counting being concordant with the 8-fold structural symmetry, is consistent with predictions derived from analysis of the primary structures of these subunits concerning inter-subunit interactions, and implies a unique topology of the subunits constituting the torodial ring in CCT. The series of subunit-subunit association patterns determined from CCT micro-complexes has provided information to infer, from the 5040 (7!factorial) combinatorial possibilities, one probable subunit orientation within the torodial ring.

    The EMBO journal 1997;16;14;4311-6

  • Cytoplasmic chaperonin complexes enter neurites developing in vitro and differ in subunit composition within single cells.

    Roobol A, Holmes FE, Hayes NV, Baines AJ and Carden MJ

    Research School of Biosciences, University of Kent at Canterbury, UK.

    Chaperonins containing t-complex polypeptide-1 (CCT) are cytosolic molecular chaperone particles implicated especially in the biogenesis of cytoskeletal proteins by promoting the correct folding of the major ubiquitous cytoskeletal components, tubulin and actin. We have purified cytosolic chaperonins from the ND7/23 cell line, determined their subunit composition and examined changes in the intracellular locations of their components during differentiation of ND7/23 cells to a neuronal phenotype by using immunocytochemistry and immunoblots. Chaperonins containing the CCT alpha (TCP1) subunit enter neuritic processes and are particularly noticeable at the leading edge of growth cone-like structures where they co-localise with actin. Chaperonins containing three other components (CCT beta, epsilon and gamma), however, remain predominantly restricted to perikaryal cytoplasm. These findings suggest a heterogeneous population of chaperonin particles within single differentiated ND7/23 cells and this may reflect specialisation of chaperonin function in different cytoplasmic compartments of a neurone. Further, since ribosomes do not enter neurites while CCT alpha-containing chaperonins do, the latter may play roles, subsequent to translation, which influence cytoskeletal elaboration during neuritogenesis.

    Funded by: Wellcome Trust

    Journal of cell science 1995;108 ( Pt 4);1477-88

  • Prediction of the coding sequences of unidentified human genes. III. The coding sequences of 40 new genes (KIAA0081-KIAA0120) deduced by analysis of cDNA clones from human cell line KG-1.

    Nagase T, Miyajima N, Tanaka A, Sazuka T, Seki N, Sato S, Tabata S, Ishikawa K, Kawarabayasi Y, Kotani H et al.

    Kazusa DNA Research Institute, Chiba, Japan.

    We isolated full-length cDNA clones from size-fractionated cDNA libraries of human immature myeloid cell line KG-1, and the coding sequences of 40 genes were newly predicted. A computer search of the GenBank/EMBL databases indicated that the sequences of 14 genes were unrelated to any reported genes, while the remaining 26 genes carried some sequences with similarities to known genes. Significant transmembrane domains were identified in 17 genes, and protein motifs that matched those in the PROSITE motif database were identified in 11 genes. Northern hybridization analysis with 18 different cells and tissues demonstrated that 10 genes were apparently expressed in a cell-specific or tissue-specific manner. Among the genes predicted, half were isolated from the medium-sized cDNA library and the other half from the small-sized cDNA library, and their average sizes were 4 kb and 1.4 kb, respectively. As judged by Northern hybridization profiles, small-sized cDNAs appeared to be expressed more ubiquitously and abundantly in various tissues, compared with that of medium-sized cDNAs.

    DNA research : an international journal for rapid publication of reports on genes and genomes 1995;2;1;37-43

  • Identification of six Tcp-1-related genes encoding divergent subunits of the TCP-1-containing chaperonin.

    Kubota H, Hynes G, Carne A, Ashworth A and Willison K

    Institute of Cancer Research, Chester Beatty Laboratories, London, UK.

    Background: TCP-1 is a 60 kD subunit of a cytosolic hetero-oligomeric chaperone that is known to be involved in the folding of actin and tubulin. This protein is a member of the chaperonin family, which includes Escherichia coli GroEL, the mitochondrial heat-shock protein Hsp60, the plastid Rubisco-subunit-binding protein and the archaebacterial protein TF55. These chaperonins assist the folding of proteins upon ATP hydrolysis.

    Results: Using two-dimensional gel analysis, we have identified nine different subunits of TCP-1-containing chaperonin complexes from mammalian testis and seven different subunits of such complexes from mouse F9 cells. We have isolated full-length mouse cDNAs encoding six novel TCP-1-related polypeptides and show that these cDNAs encode subunits of the TCP-1-containing cytosolic chaperonin. These subunits are between 531 and 545 residues in length. Their sequences are 25-36% identical to one another, 27-35% identical to that of TCP-1 and 32-39% identical to that of the archaebacterial chaperonin, TF55. We have named these genes, Cctb, Cctg, Cctd, Ccte, Cctz and Ccth, which encode the CCT beta, CCT gamma, CCT delta, CCT epsilon, CCT zeta and CCT eta subunits, respectively, of the 'Chaperonin Containing TCP-1' (CCT). All the CCT subunits contain motifs that are also shared by all other known chaperonins of prokaryotes and eukaryotic organelles, and that probably relate to their common ATPase function.

    Conclusion: It is likely that each CCT subunit has a specific, independent function, as they are highly diverged from each other but conserved from mammals to yeast. We suggest that the expansion in the number of types of CCT subunit, compared with other chaperonins, has allowed CCT to carry out the more complex functions that are required for the folding and assembly of highly evolved eukaryotic proteins.

    Current biology : CB 1994;4;2;89-99

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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