OMIMOnlineMendelianInheritanceinManAll DatabasesPubMedNucleotideProteinGenomeStructurePMCTaxonomyOMIM SearchPubMedProteinNucleotideCoreNucleotideGSSESTStructureGenomeBooksCancerChromosomesConservedDomainsdbGaP3DDomainsGeneGenomeProjectGENSATGEOProfilesGEODataSetsHomoloGeneJournalsMeSHNCBIWebSiteNLMCatalogOMIAOMIMPMCPopSetProbeProteinClustersPubChemBioAssayPubChemCompoundPubChemSubstanceSNPTaxonomyToolKitUniGeneUniSTSLimitsPreview/IndexHistoryClipboardDetailsDisplayTitlesDetailedClinicalSynopsisAllelicVariantsASN1XMLLinkOutRelatedEntriesBookLinksGeneLinksGenomeLinksGEOProfileLinksHomoloGeneLinksNucleotideLinksOMIALinksPubChemBioAssayLinksPMCLinksProteinLinksPubMed(calculated)LinksPubMed(cited)LinksSNPLinksGeneGenotypeLinksStructureLinksUniGeneLinksUniSTSLinksShow5102050100200500SendtoTextFilePrinterClipboardAll1OMIMdbSNP0OMIMUniSTS0*604222LinksACTINRELATEDPROTEIN3ACTR3AlternativetitlessymbolsARP3TEXTTheArp2/3proteincomplexhasbeenimplicatedinthecontrolofactinpolymerizationincellsThehumancomplexconsistsof7subunitstheactinrelatedproteinsARP2(ACTR2604221)andARP3(ACTR3)ARC41(ARPC1B604223)ARC34(ARPC2604224)ARC21(ARPC3604225)ARC20(ARPC4604226)andARC16(ARPC5604227)SeeACTR2foradditionalinformationabouttheArp2/3complexCLONINGBysearchinganESTdatabasewithpeptidesequencesfromthe7subunitsofthehumanARP2/3complexWelchetal(1997)identifiedfulllengthhumancDNAsencodingeachsubunitTheARP3cDNAencodesadeduced418aminoacidproteinthatisidenticaltobovineArp359%identicaltoSpombeArp3and58%identicaltoScerevisiaeArp3ARP3localizestothelamellipodiaofstationaryandlocomotingfibroblastsItalsolocalizestotheactintailsassembledbymovingintracellularListeriamonocytogenesbacteriaandtoactincloudssurroundingstationaryLmonocytogenes(Welchetal1997)ARP3wasnotdetectedincellularbundlesofactinfilamentsMacheskyetal(1997)purifiedtheARP2/3complexfromhumanneutrophilsandsequencedpeptidesfromeachofthesubunitsWesternblotanalysisdetectedARP3andARC34inallhumantissuestestedBIOCHEMICALFEATURESVolkmannetal(2001)performedelectroncryomicroscopyand3dimensionalreconstructionofAcanthamoebacastellaniiandScerevisiaeArp2/3complexesboundtotheWASP(301000)carboxyterminaldomainAsymmetricoblateellipsoidswererevealedImageanalysisofactinbranchesindicatedthatthecomplexbindsthesideofthemotherfilamentandARP2andARP3arethefirst2subunitsofthedaughterfilamentComparisontotheactinfreeWASPactivatedcomplexessuggeststhatbranchinitiationinvolveslargescalestructuralrearrangementswithinARP2/3Robinsonetal(2001)determinedthecrystalstructureofbovineARP2/3complexat20angstromresolutionARP2andARP3arefoldedlikeactinwithdistinctivesurfacefeaturesSubunitsARPC2andARPC4inthecoreofthecomplexassociatethroughlongcarboxyterminalalphahelicesandhavesimilarlyfoldedaminoterminalalpha/betadomainsARPC1isa7bladebetapropellerwithaninsertionthatmayassociatewiththesideofanactinfilamentARPC3andARPC5areglobularalphahelicalsubunitsRobinsonetal(2001)predictedthatWASP/SCARproteinsactivateARP2/3complexbybringingARP2intoproximitywithARP3fornucleationofabranchonthesideofapreexistingactinfilamentREFERENCES1MacheskyLMReevesEWientjesFMattheyseFJGroganATottyNFBurlingameALHsuanJJSegalAWMammalianactinrelatedprotein2/3complexlocalizestoregionsoflamellipodialprotrusionandiscomposedofevolutionarilyconservedproteinsBiochemJ3281051121997PubMedID93598402RobinsonRCTurbedskyKKaiserDAMarchandJBHiggsHNChoeSPollardTDCrystalstructureofArp2/3complexScience294167916842001PubMedID117210453VolkmannNAmannKJStoilovaMcPhieSEgileCWinterDCHazelwoodLHeuserJELiRPollardTDHaneinDStructureofArp2/3complexinitsactivatedstateandinactinfilamentbranchjunctionsScience293245624592001PubMedID115334424WelchMDDePaceAHVermaSIwamatsuAMitchisonTJThehumanArp2/3complexiscomposedofevolutionarilyconservedsubunitsandislocalizedtocellularregionsofdynamicactinfilamentassemblyJCellBiol1383753841997PubMedID92300795WelchMDIwamatsuAMitchisonTJActinpolymerizationisinducedbyArp2/3proteincomplexatthesurfaceofListeriamonocytogenesNature3852652691997PubMedID9000076CONTRIBUTORSAdaHamoshupdated1/10/2002AdaHamoshupdated10/11/2001PattiMShermanupdated10/29/1999CREATIONDATEPattiMSherman10/8/1999EDITHISTORYalopez1/10/2002alopez1/10/2002alopez10/11/2001mgross11/1/1999psherman10/29/1999mgross10/15/1999psherman10/12/1999psherman10/12/1999Copyright©19662007JohnsHopkinsUniversityDisplayTitlesDetailedClinicalSynopsisAllelicVariantsASN1XMLLinkOutRelatedEntriesBookLinksGeneLinksGenomeLinksGEOProfileLinksHomoloGeneLinksNucleotideLinksOMIALinksPubChemBioAssayLinksPMCLinksProteinLinksPubMed(calculated)LinksPubMed(cited)LinksSNPLinksGeneGenotypeLinksStructureLinksUniGeneLinksUniSTSLinksShow5102050100200500SendtoTextFilePrinterClipboardDisclaimerWritetotheHelpDeskPrivacyPolicyNCBINLMNIH