G2Cdb::Gene report

Gene id
Gene symbol
Homo sapiens
actin related protein 2/3 complex, subunit 2, 34kDa
G00000541 (Mus musculus)

Databases (8)

ENSG00000163466 (Ensembl human gene)
10109 (Entrez Gene)
72 (G2Cdb plasticity & disease)
ARPC2 (GeneCards)
604224 (OMIM)
Marker Symbol
Protein Expression
1994 (human protein atlas)
Protein Sequence
O15144 (UniProt)

Synonyms (2)

  • ARC34
  • p34-Arc

Literature (24)

Pubmed - other

  • Genetic analysis in a Dutch study sample identifies more ulcerative colitis susceptibility loci and shows their additive role in disease risk.

    Festen EA, Stokkers PC, van Diemen CC, van Bodegraven AA, Boezen HM, Crusius BJ, Hommes DW, van der Woude CJ, van der Woude JC, Balschun T, Verspaget HW, Schreiber S, de Jong DJ, Franke A, Dijkstra G, Wijmenga C and Weersma RK

    Department of Gastroenterology and Hepatology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.

    Objectives: Genetic susceptibility is known to make a major contribution to the pathogenesis of ulcerative colitis (UC). Recently, three studies, including a genome-wide association study (GWAS), reported novel UC risk loci.

    Methods: The top-20 single-nucleotide polymorphisms (SNPs) from the first UC-GWAS were genotyped, as part of the study's replication phase, in 561 UC cases and 728 controls from our Dutch UC study sample. We genotyped eight SNPs identified in two more studies, in these individuals, and replicated all significantly associated SNPs in an additional 894 UC cases and 1,174 controls from our Dutch UC study sample. A combined analysis for all patients (n=1,455) and controls (n=1,902) was performed. Dose-response models were constructed with the associated risk alleles.

    Results: We found 12 SNPs tagging ten loci, including HLA-DRA, IL10, IL23R, JAK2, S100Z, ARPC2, and ECM1, to be associated with UC. We identified 10q26, flagged by the UC-GWAS but not confirmed in its replication phase, as a UC locus and found a trend toward association for GAS7. No association with disease localization or severity was found. The dose-response models show that individuals carrying 11 or more risk alleles have an odds ratio of 8.2 (confidence interval 3.0-22.8) for UC susceptibility.

    Conclusions: We confirmed the association of multiple loci with UC in the Dutch population and found evidence for association of 10q26 and a trend suggesting association for GAS7. Genetic models show that multiple risk loci in an individual increase the risk for developing UC.

    The American journal of gastroenterology 2010;105;2;395-402

  • Sequence variants in IL10, ARPC2 and multiple other loci contribute to ulcerative colitis susceptibility.

    Franke A, Balschun T, Karlsen TH, Sventoraityte J, Nikolaus S, Mayr G, Domingues FS, Albrecht M, Nothnagel M, Ellinghaus D, Sina C, Onnie CM, Weersma RK, Stokkers PC, Wijmenga C, Gazouli M, Strachan D, McArdle WL, Vermeire S, Rutgeerts P, Rosenstiel P, Krawczak M, Vatn MH, IBSEN study group, Mathew CG and Schreiber S

    Institute for Clinical Molecular Biology, Christian-Albrechts-University, Kiel 24105, Germany.

    Inflammatory bowel disease (IBD) typically manifests as either ulcerative colitis (UC) or Crohn's disease (CD). Systematic identification of susceptibility genes for IBD has thus far focused mainly on CD, and little is known about the genetic architecture of UC. Here we report a genome-wide association study with 440,794 SNPs genotyped in 1,167 individuals with UC and 777 healthy controls. Twenty of the most significantly associated SNPs were tested for replication in three independent European case-control panels comprising a total of 1,855 individuals with UC and 3,091 controls. Among the four consistently replicated markers, SNP rs3024505 immediately flanking the IL10 (interleukin 10) gene on chromosome 1q32.1 showed the most significant association in the combined verification samples (P = 1.35 x 10(-12); OR = 1.46 (1.31-1.62)). The other markers were located in ARPC2 and in the HLA-BTNL2 region. Association between rs3024505 and CD (1,848 cases, 1,804 controls) was weak (P = 0.013; OR = 1.17 (1.01-1.34)). IL10 is an immunosuppressive cytokine that has long been proposed to influence IBD pathophysiology. Our findings strongly suggest that defective IL10 function is central to the pathogenesis of the UC subtype of IBD.

    Funded by: Medical Research Council: G0000934, MC_QA137934; Wellcome Trust: 068545/Z/02

    Nature genetics 2008;40;11;1319-23

  • Overexpression of N-WASP in the brain of human epilepsy.

    Xiao F, Wang XF, Li JM, Xi ZQ, Lu Y, Wang L, Zeng Y, Guan LF and Yuan J

    Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 You Yi Road, Chongqing 400016, China.

    Neuronal circuit remodeling is the most critical pathological characteristic closely associated with the initiation and maintenance of epilepsy; however, the exact mechanisms of neuronal remodeling need further elucidation. Neuronal Wiskott-Aldrich syndrome protein (N-WASP) is a key regulator of the actin cytoskeleton that causes actin polymerization and thus neurite extension. Our previous research demonstrated that the upstream regulator of N-WASP, cell division cycle 42 GTP-binding protein (Cdc42), is significantly upregulated in the brains of patients with intractable epilepsy (IE). In addition, cDNA microarray analysis has shown that gene expression of N-WASP is notably enhanced in the epileptic brain, suggesting a possible role for N-WASP in epileptogenesis. Here, we investigated the expression of N-WASP and its downstream effector, actin-related protein 2/3 (Arp2/3), at the protein level in the temporal lobe of IE patient brains to explore its possible role in the genesis of IE. Forty surgical samples from brains of patients with IE and 20 control brain tissues were obtained for this study. The expression of N-WASP in the anterior temporal neocortex was detected using immunohistochemistry, immunofluorescence and western blotting; Arp2/3 expression was detected by western blotting. Compared with controls, N-WASP expression in brains of IE patients was significantly higher; similarly, Arp2/3 level was markedly increased in the IE patient group. These results suggest that increased expression of N-WASP in the human brain may be associated with human IE.

    Brain research 2008;1233;168-75

  • 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

  • Coronin 1B coordinates Arp2/3 complex and cofilin activities at the leading edge.

    Cai L, Marshall TW, Uetrecht AC, Schafer DA and Bear JE

    Lineberger Comprehensive Cancer Center and Department of Cell and Developmental Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.

    Actin filament formation and turnover within the treadmilling actin filament array at the leading edge of migrating cells are interdependent and coupled, but the mechanisms coordinating these two activities are not understood. We report that Coronin 1B interacts simultaneously with Arp2/3 complex and Slingshot (SSH1L) phosphatase, two regulators of actin filament formation and turnover, respectively. Coronin 1B inhibits filament nucleation by Arp2/3 complex and this inhibition is attenuated by phosphorylation of Coronin 1B at Serine 2, a site targeted by SSH1L. Coronin 1B also directs SSH1L to lamellipodia where SSH1L likely regulates Cofilin activity via dephosphorylation. Accordingly, depleting Coronin 1B increases phospho-Cofilin levels, and alters lamellipodial dynamics and actin filament architecture at the leading edge. We conclude that Coronin 1B's coordination of filament formation by Arp2/3 complex and filament turnover by Cofilin is required for effective lamellipodial protrusion and cell migration.

    Funded by: NCI NIH HHS: 1U54 CA 119343, CA 16086, P30 CA016086; NIGMS NIH HHS: GM 067222, R01 GM067222, R01 GM083035, R01 GM083035-01

    Cell 2007;128;5;915-29

  • Large-scale mapping of human protein-protein interactions by mass spectrometry.

    Ewing RM, Chu P, Elisma F, Li H, Taylor P, Climie S, McBroom-Cerajewski L, Robinson MD, O'Connor L, Li M, Taylor R, Dharsee M, Ho Y, Heilbut A, Moore L, Zhang S, Ornatsky O, Bukhman YV, Ethier M, Sheng Y, Vasilescu J, Abu-Farha M, Lambert JP, Duewel HS, Stewart II, Kuehl B, Hogue K, Colwill K, Gladwish K, Muskat B, Kinach R, Adams SL, Moran MF, Morin GB, Topaloglou T and Figeys D

    Protana, Toronto, Ontario, Canada.

    Mapping protein-protein interactions is an invaluable tool for understanding protein function. Here, we report the first large-scale study of protein-protein interactions in human cells using a mass spectrometry-based approach. The study maps protein interactions for 338 bait proteins that were selected based on known or suspected disease and functional associations. Large-scale immunoprecipitation of Flag-tagged versions of these proteins followed by LC-ESI-MS/MS analysis resulted in the identification of 24,540 potential protein interactions. False positives and redundant hits were filtered out using empirical criteria and a calculated interaction confidence score, producing a data set of 6463 interactions between 2235 distinct proteins. This data set was further cross-validated using previously published and predicted human protein interactions. In-depth mining of the data set shows that it represents a valuable source of novel protein-protein interactions with relevance to human diseases. In addition, via our preliminary analysis, we report many novel protein interactions and pathway associations.

    Molecular systems biology 2007;3;89

  • Phosphorylation of coronin 1B by protein kinase C regulates interaction with Arp2/3 and cell motility.

    Cai L, Holoweckyj N, Schaller MD and Bear JE

    Lineberger Comprehensive Cancer Center and Department of Cell & Developmental Biology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, USA.

    Coronins are a conserved family of WD repeat-containing, actin-binding proteins that regulate cell motility in a variety of model organisms. Our results show that Coronin 1B is a ubiquitously expressed member of the mammalian Coronin gene family that co-localizes with the Arp2/3 complex at the leading edge of fibroblasts, and co-immunoprecipitates with this complex. Pharmacological experiments show that the interaction between Coronin 1B and the Arp2/3 complex is regulated by protein kinase C (PKC) phosphorylation. Coronin 1B is phosphorylated by PKC both in vitro and in vivo. Using tryptic peptide mapping and mutagenesis, we have identified serine 2 (Ser-2) on Coronin 1B as the major residue phosphorylated by PKC in vivo. Rat2 fibroblasts expressing the Coronin 1B S2A mutant show enhanced ruffling in response to phorbol 12-myristate 13-acetate (PMA) and increased speed in single cell tracking assays. Cells expressing the Coronin 1B S2D mutant have attenuated PMA-induced ruffling and slower cell speed. Expression of the S2A mutant partially protects cells from the inhibitory effects of PMA on cell speed, whereas expression of the S2D mutant renders cells hypersensitive to its effects. These data demonstrate that Coronin 1B regulates leading edge dynamics and cell motility in fibroblasts, and that its ability to control motility and interactions with the Arp2/3 complex are regulated by PKC phosphorylation at Ser-2. Furthermore, Coronin 1B phosphorylation is responsible for a significant fraction of the effects of PMA on fibroblast motility.

    Funded by: NCI NIH HHS: CA90901; NHLBI NIH HHS: HL45100

    The Journal of biological chemistry 2005;280;36;31913-23

  • Golgi-localized GAP for Cdc42 functions downstream of ARF1 to control Arp2/3 complex and F-actin dynamics.

    Dubois T, Paléotti O, Mironov AA, Fraisier V, Stradal TE, De Matteis MA, Franco M and Chavrier P

    Membrane and Cytoskeleton Dynamics Group, Institut Curie, CNRS-UMR144, 75248 Paris, France.

    The small GTP-binding ADP-ribosylation factor 1 (ARF1) acts as a master regulator of Golgi structure and function through the recruitment and activation of various downstream effectors. It has been proposed that members of the Rho family of small GTPases also control Golgi function in coordination with ARF1, possibly through the regulation of Arp2/3 complex and actin polymerization on Golgi membranes. Here, we identify ARHGAP10--a novel Rho GTPase-activating protein (Rho-GAP) that is recruited to Golgi membranes through binding to GTP-ARF1. We show that ARHGAP10 functions preferentially as a GAP for Cdc42 and regulates the Arp2/3 complex and F-actin dynamics at the Golgi through the control of Cdc42 activity. Our results establish a role for ARHGAP10 in Golgi structure and function at the crossroads between ARF1 and Cdc42 signalling pathways.

    Funded by: Telethon: GP0203Y01

    Nature cell biology 2005;7;4;353-64

  • Nucleolar proteome dynamics.

    Andersen JS, Lam YW, Leung AK, Ong SE, Lyon CE, Lamond AI and Mann M

    Department of Biochemistry and Molecular Biology, Campusvej 55, DK-5230 Odense M, Denmark.

    The nucleolus is a key organelle that coordinates the synthesis and assembly of ribosomal subunits and forms in the nucleus around the repeated ribosomal gene clusters. Because the production of ribosomes is a major metabolic activity, the function of the nucleolus is tightly linked to cell growth and proliferation, and recent data suggest that the nucleolus also plays an important role in cell-cycle regulation, senescence and stress responses. Here, using mass-spectrometry-based organellar proteomics and stable isotope labelling, we perform a quantitative analysis of the proteome of human nucleoli. In vivo fluorescent imaging techniques are directly compared to endogenous protein changes measured by proteomics. We characterize the flux of 489 endogenous nucleolar proteins in response to three different metabolic inhibitors that each affect nucleolar morphology. Proteins that are stably associated, such as RNA polymerase I subunits and small nuclear ribonucleoprotein particle complexes, exit from or accumulate in the nucleolus with similar kinetics, whereas protein components of the large and small ribosomal subunits leave the nucleolus with markedly different kinetics. The data establish a quantitative proteomic approach for the temporal characterization of protein flux through cellular organelles and demonstrate that the nucleolar proteome changes significantly over time in response to changes in cellular growth conditions.

    Funded by: Wellcome Trust: 073980

    Nature 2005;433;7021;77-83

  • 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

  • Decreased expression of the seven ARP2/3 complex genes in human gastric cancers.

    Kaneda A, Kaminishi M, Sugimura T and Ushijima T

    National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan.

    The Arp2/3 complex and filamins play important roles in organization of actin cytoskeleton, and thus in cellular morphology and locomotion. We recently identified decreased expression of a gene for one of seven subunits of the Arp2/3 complex, the p41-Arc gene, and silencing of a filamin gene, the FLNc gene, in human gastric cancers. In this study, gene expressions of the seven subunits of the Arp2/3 complex, including p41-Arc, and their methylation statuses were analyzed in human gastric cancers. Quantitative real-time RT-PCR analysis of 32 primary gastric cancer samples and eight gastric cancer cell lines revealed that expressions of all the seven genes were significantly decreased. All the 32 primary cancer samples showed decreased expression of at least one subunit, and 25 samples showed decreased expressions of four or more of the seven subunits. Methylation-specific PCR analysis showed that none of the CpG islands in the 5' regions of the six genes other than p41-Arc were methylated in primary gastric cancers or cell lines. The consistent decrease of the Arp2/3 complex genes and its important role in actin organization suggested that the decrease could be involved in cancer phenotypes, such as dysplastic morphology.

    Cancer letters 2004;212;2;203-10

  • 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

  • Exploring proteomes and analyzing protein processing by mass spectrometric identification of sorted N-terminal peptides.

    Gevaert K, Goethals M, Martens L, Van Damme J, Staes A, Thomas GR and Vandekerckhove J

    Department of Medical Protein Research, Flanders Interuniversity Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, B-9000 Ghent, Belgium. kris.gevaert@rug.ac.be

    Current non-gel techniques for analyzing proteomes rely heavily on mass spectrometric analysis of enzymatically digested protein mixtures. Prior to analysis, a highly complex peptide mixture is either separated on a multidimensional chromatographic system or it is first reduced in complexity by isolating sets of representative peptides. Recently, we developed a peptide isolation procedure based on diagonal electrophoresis and diagonal chromatography. We call it combined fractional diagonal chromatography (COFRADIC). In previous experiments, we used COFRADIC to identify more than 800 Escherichia coli proteins by tandem mass spectrometric (MS/MS) analysis of isolated methionine-containing peptides. Here, we describe a diagonal method to isolate N-terminal peptides. This reduces the complexity of the peptide sample, because each protein has one N terminus and is thus represented by only one peptide. In this new procedure, free amino groups in proteins are first blocked by acetylation and then digested with trypsin. After reverse-phase (RP) chromatographic fractionation of the generated peptide mixture, internal peptides are blocked using 2,4,6-trinitrobenzenesulfonic acid (TNBS); they display a strong hydrophobic shift and therefore segregate from the unaltered N-terminal peptides during a second identical separation step. N-terminal peptides can thereby be specifically collected for further liquid chromatography (LC)-MS/MS analysis. Omitting the acetylation step results in the isolation of non-lysine-containing N-terminal peptides from in vivo blocked proteins.

    Nature biotechnology 2003;21;5;566-9

  • Cadherin-directed actin assembly: E-cadherin physically associates with the Arp2/3 complex to direct actin assembly in nascent adhesive contacts.

    Kovacs EM, Goodwin M, Ali RG, Paterson AD and Yap AS

    Department of Physiology and Pharmacology, School of Biomedical Science, 4072, Brisbane, Australia.

    Cadherin cell adhesion molecules are major determinants of tissue patterning which function in cooperation with the actin cytoskeleton. In the context of stable adhesion, cadherin/catenin complexes are often envisaged to passively scaffold onto cortical actin filaments. However, cadherins also form dynamic adhesive contacts during wound healing and morphogenesis. Here actin polymerization has been proposed to drive cell surfaces together, although F-actin reorganization also occurs as cell contacts mature. The interaction between cadherins and actin is therefore likely to depend on the functional state of adhesion. We sought to analyze the relationship between cadherin homophilic binding and cytoskeletal activity during early cadherin adhesive contacts. Dissecting the specific effect of cadherin ligation alone on actin regulation is difficult in native cell-cell contacts, due to the range of juxtacrine signals that can arise when two cell surfaces adhere. We therefore activated homophilic ligation using a specific functional recombinant protein. We report the first evidence that E-cadherin associates with the Arp2/3 complex actin nucleator and demonstrate that cadherin binding can exert an active, instructive influence on cells to mark sites for actin assembly at the cell surface.

    Current biology : CB 2002;12;5;379-82

  • Crystal structure of Arp2/3 complex.

    Robinson RC, Turbedsky K, Kaiser DA, Marchand JB, Higgs HN, Choe S and Pollard TD

    Structural Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.

    We determined a crystal structure of bovine Arp2/3 complex, an assembly of seven proteins that initiates actin polymerization in eukaryotic cells, at 2.0 angstrom resolution. Actin-related protein 2 (Arp2) and Arp3 are folded like actin, with distinctive surface features. Subunits ARPC2 p34 and ARPC4 p20 in the core of the complex associate through long carboxyl-terminal alpha helices and have similarly folded amino-terminal alpha/beta domains. ARPC1 p40 is a seven-blade beta propeller with an insertion that may associate with the side of an actin filament. ARPC3 p21 and ARPC5 p16 are globular alpha-helical subunits. We predict that WASp/Scar proteins activate Arp2/3 complex by bringing Arp2 into proximity with Arp3 for nucleation of a branch on the side of a preexisting actin filament.

    Funded by: NIGMS NIH HHS: GM-26132, GM-26338, GM-56653

    Science (New York, N.Y.) 2001;294;5547;1679-84

  • Reconstitution of human Arp2/3 complex reveals critical roles of individual subunits in complex structure and activity.

    Gournier H, Goley ED, Niederstrasser H, Trinh T and Welch MD

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.

    The Arp2/3 complex is a seven-protein assembly that is critical for actin nucleation and branching in cells. Here we report the reconstitution of active human Arp2/3 complex after expression of all seven subunits in insect cells. Expression of partial complexes revealed that a heterodimer of the p34 and p20 subunits constitutes a critical structural core of the complex, whereas the remaining subunits are peripherally located. Arp3 is crucial for nucleation, consistent with it being a structural component of the nucleation site. p41, p21, and p16 contribute differently to nucleation and stimulation by ActA and WASP, whereas p34/p20 bind actin filaments and likely function in actin branching. This study reveals that the nucleating and organizing functions of Arp2/3 complex subunits are separable, indicating that these activities may be differentially regulated in cells.

    Funded by: NIGMS NIH HHS: GM59609, R01 GM059609, R01 GM059609-03

    Molecular cell 2001;8;5;1041-52

  • Interactions among subunits of human Arp2/3 complex: p20-Arc as the hub.

    Zhao X, Yang Z, Qian M and Zhu X

    Shanghai Research Center of Life Sciences and Open Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031, China.

    The Arp2/3 complex is critical for nucleation and crosslinking of actin filaments. To gain insight into its subunit topology and assembly pathway, we systematically examined interactions among subunits of human Arp2/3 complex by yeast two-hybrid assays. It was shown that p20-Arc was able to interact with p21-Arc, p34-Arc, and p16-Arc, respectively. In contrast, p41-Arc only interacted with p20-Arc/p16-Arc heterodimer. In addition, we found that structural integrity was important for association between p20-Arc and p21-Arc, while the N-terminal half of p34-Arc was dispensable for its binding to p20-Arc. Our data suggest a key role of p20-Arc and a multistep pathway for the complex formation.

    Biochemical and biophysical research communications 2001;280;2;513-7

  • Cortactin localization to sites of actin assembly in lamellipodia requires interactions with F-actin and the Arp2/3 complex.

    Weed SA, Karginov AV, Schafer DA, Weaver AM, Kinley AW, Cooper JA and Parsons JT

    Department of Microbiology and Cancer Center, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA.

    Cortactin is an actin-binding protein that is enriched within the lamellipodia of motile cells and in neuronal growth cones. Here, we report that cortactin is localized with the actin-related protein (Arp) 2/3 complex at sites of actin polymerization within the lamellipodia. Two distinct sequence motifs of cortactin contribute to its interaction with the cortical actin network: the fourth of six tandem repeats and the amino-terminal acidic region (NTA). Cortactin variants lacking either the fourth tandem repeat or the NTA failed to localize at the cell periphery. Tandem repeat four was necessary for cortactin to stably bind F-actin in vitro. The NTA region interacts directly with the Arp2/3 complex based on affinity chromatography, immunoprecipitation assays, and binding assays using purified components. Cortactin variants containing the NTA region were inefficient at promoting Arp2/3 actin nucleation activity. These data provide strong evidence that cortactin is specifically localized to sites of dynamic cortical actin assembly via simultaneous interaction with F-actin and the Arp2/3 complex. Cortactin interacts via its Src homology 3 (SH3) domain with ZO-1 and the SHANK family of postsynaptic density 95/dlg/ZO-1 homology (PDZ) domain-containing proteins, suggesting that cortactin contributes to the spatial organization of sites of actin polymerization coupled to selected cell surface transmembrane receptor complexes.

    Funded by: NCI NIH HHS: CA29243, CA40042, F32 CA075695, P01 CA040042, R01 CA029243, R37 CA029243; NIGMS NIH HHS: GM38542, R01 GM038542, R01 GM038542-11S1

    The Journal of cell biology 2000;151;1;29-40

  • Composite co-activator ARC mediates chromatin-directed transcriptional activation.

    Näär AM, Beaurang PA, Zhou S, Abraham S, Solomon W and Tjian R

    Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.

    Gene activation in eukaryotes is regulated by complex mechanisms in which the recruitment and assembly of the transcriptional machinery is directed by gene- and cell-type-specific DNA-binding proteins. When DNA is packaged into chromatin, the regulation of gene activation requires new classes of chromatin-targeting activity. In humans, a multisubunit cofactor functions in a chromatin-selective manner to potentiate synergistic gene activation by the transcriptional activators SREBP-1a and Sp1. Here we show that this activator-recruited cofactor (ARC) interacts directly with several different activators, including SREBP-1a, VP16 and the p65 subunit of NF-kappaB, and strongly enhances transcription directed by these activators in vitro with chromatin-assembled DNA templates. The ARC complex consists of 16 or more subunits; some of these are novel gene products, whereas others are present in other multisubunit cofactors, such as CRSP, NAT and mammalian Mediator. Detailed analysis indicates that the ARC complex is probably identical to the nuclear hormone-receptor cofactor DRIP. Thus, ARC/DRIP is a large composite co-activator that belongs to a family of related cofactors and is targeted by different classes of activator to mediate transcriptional stimulation.

    Nature 1999;398;6730;828-32

  • Mammalian actin-related protein 2/3 complex localizes to regions of lamellipodial protrusion and is composed of evolutionarily conserved proteins.

    Machesky LM, Reeves E, Wientjes F, Mattheyse FJ, Grogan A, Totty NF, Burlingame AL, Hsuan JJ and Segal AW

    Department of Medicine, University College London, U.K.

    Human neutrophils contain a complex of proteins similar to the actin-related protein 2/3 (Arp2/3) complex of Acanthamoeba. We have obtained peptide sequence information for each member of the putative seven-protein complex previously described for Acanthamoeba and human platelets. From the peptide sequences we have identified cDNA species encoding three novel proteins in this complex. We find that in addition to Arp2 and Arp3, this complex contains a relative of the human (Suppressor of Profilin) SOP2Hs protein and four previously unknown proteins. These proteins localize in the cytoplasm of fibroblasts that lack lamellipodia, but are enriched in lamellipodia on stimulation with serum or platelet-derived growth factor. We propose a conserved and dynamic role for this complex in the organization of the actin cytoskeleton.

    Funded by: Wellcome Trust

    The Biochemical journal 1997;328 ( Pt 1);105-12

  • The human Arp2/3 complex is composed of evolutionarily conserved subunits and is localized to cellular regions of dynamic actin filament assembly.

    Welch MD, DePace AH, Verma S, Iwamatsu A and Mitchison TJ

    Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94143-0450, USA. welch@cgl.ucsf.edu

    The Arp2/3 protein complex has been implicated in the control of actin polymerization in cells. The human complex consists of seven subunits which include the actin related proteins Arp2 and Arp3, and five others referred to as p41-Arc, p34-Arc, p21-Arc, p20-Arc, and p16-Arc (p omplex). We have determined the predicted amino acid sequence of all seven subunits. Each has homologues in diverse eukaryotes, implying that the structure and function of the complex has been conserved through evolution. Human Arp2 and Arp3 are very similar to family members from other species. p41-Arc is a new member of the Sop2 family of WD (tryptophan and aspartate) repeat-containing proteins and may be posttranslationally modified, suggesting that it may be involved in regulating the activity and/or localization of the complex. p34-Arc, p21-Arc, p20-Arc, and p16-Arc define novel protein families. We sought to evaluate the function of the Arp2/3 complex in cells by determining its intracellular distribution. Arp3, p34-Arc, and p21-Arc were localized to the lamellipodia of stationary and locomoting fibroblasts, as well to Listeria monocytogenes assembled actin tails. They were not detected in cellular bundles of actin filaments. Taken together with the ability of the Arp2/3 complex to induce actin polymerization, these observations suggest that the complex promotes actin assembly in lamellipodia and may participate in lamellipodial protrusion.

    Funded by: NIGMS NIH HHS: GM48027

    The Journal of cell biology 1997;138;2;375-84

  • Actin polymerization is induced by Arp2/3 protein complex at the surface of Listeria monocytogenes.

    Welch MD, Iwamatsu A and Mitchison TJ

    Department of Cellular and Molecular Pharmacology, University of California at San Francisco, 94143, USA. welch@cgl.ucsf.edu

    The pathogenic bacterium Listeria monocytogenes is capable of directed movement within the cytoplasm of infected host cells. Propulsion is thought to be driven by actin polymerization at the bacterial cell surface, and moving bacteria leave in their wake a tail of actin filaments. Determining the mechanism by which L. monocytogenes polymerizes actin may aid the understanding of how actin polymerization is controlled in the cell. Actin assembly by L. monocytogenes requires the bacterial surface protein ActA and protein components present in host cell cytoplasm. We have purified an eight-polypeptide complex that possesses the properties of the host-cell actin polymerization factor. The pure complex is sufficient to initiate ActA-dependent actin polymerization at the surface of L. monocytogenes, and is required to mediate actin tail formation and motility. Two subunits of this protein complex are actin-related proteins (ARPs) belonging to the Arp2 and Arp3 subfamilies. The Arp3 subunit localizes to the surface of stationary bacteria and the tails of motile bacteria in tissue culture cells infected with L. monocytogenes; this is consistent with a role for the complex in promoting actin assembly in vivo. The activity and subunit composition of the Arp2/3 complex suggests that it forms a template that nucleates actin polymerization.

    Nature 1997;385;6613;265-9

  • Generation of an integrated transcription map of the BRCA2 region on chromosome 13q12-q13.

    Couch FJ, Rommens JM, Neuhausen SL, Bélanger C, Dumont M, Abel K, Bell R, Berry S, Bogden R, Cannon-Albright L, Farid L, Frye C, Hattier T, Janecki T, Jiang P, Kehrer R, Leblanc JF, McArthur-Morrison J, Meney D, Miki Y, Peng Y, Samson C, Schroeder M, Snyder SC, Simard J et al.

    Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA.

    An integrated approach involving physical mapping, identification of transcribed sequences, and computational analysis of genomic sequence was used to generate a detailed transcription map of the 1. 0-Mb region containing the breast cancer susceptibility locus BRCA2 on chromosome 13q12-q13. This region is included in the genetic interval bounded by D13S1444 and D13S310. Retrieved sequences from exon amplification or hybrid selection procedures were grouped into physical intervals and subsequently grouped into transcription units by clone overlap. Overlap was established by direct hybridization, cDNA library screening, PCR cDNA linking (island hopping), and/or sequence alignment. Extensive genomic sequencing was performed in an effort to understand transcription unit organization. In total, approximately 500 kb of genomic sequence was completed. The transcription units were further characterized by hybridization to RNA from a series of human tissues. Evidence for seven genes, two putative pseudogenes, and nine additional putative transcription units was obtained. One of the transcription units was recently identified as BRCA2 but all others are novel genes of unknown function as only limited alignment to sequences in public databases was observed. One large gene with a transcript size of 10.7 kb showed significant similarity to a gene predicted by the Caenorhabditis elegans genome and the Saccharomyces cerevisiae genome sequencing efforts, while another contained a motif sequence similar to the human 2',3' cyclic nucleotide 3' phosphodiesterase gene. Several retrieved transcribed sequences were not aligned into transcription units because no corresponding cDNAs were obtained when screening libraries or because of a lack of definitive evidence for splicing signals or putative coding sequence based on computational analysis. However, the presence of additional genes in the BRCA2 interval is suggested as groups of putative exons and hybrid selected clones that were transcribed in consistent orientations could be localized to common physical intervals.

    Funded by: NCI NIH HHS: CA57601, CA61231, CA67403; ...

    Genomics 1996;36;1;86-99

Gene lists (7)

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
L00000015 G2C Homo sapiens Human NRC Human orthologues of mouse NRC adapted from Collins et al (2006) 186
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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