IntAct European Bioinformatics Institute IntAct intact http://www.ebi.ac.uk/ http://www.ebi.ac.uk/intact/query/${ac} EBI-[0-9]+|IA:[0-9]+ INTerAction database (IntAct) provides an open source database and toolkit for the storage, presentation and analysis of molecular interactions. http://www.ebi.ac.uk/intact European Bioinformatics Institute; Wellcome Trust Genome Campus; Hinxton, Cambridge; CB10 1SD; United Kingdom http://www.ebi.ac.uk/intact/ ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. J. Biol. Chem. (0021-9258) 2004 Pan F., Egile C., Lipkin T., Li R. rli@hms.harvard.edu 23-MAY-2007: Contacted by JYOTI. Returned mail. yeasx Saccharomyces cerevisiae (Baker's yeast) Baker's yeast tap tandem affinity purification TAP TAP tap fingerprinting peptide massfingerprinting fingerprinting Pan F., Egile C., Lipkin T., Li R. rli@hms.harvard.edu Accepted 2007-JUN-10 by JYOTI. 23-MAY-2007: Contacted by JYOTI. Returned mail. J. Biol. Chem. (0021-9258) 2004 ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. J. Biol. Chem. (0021-9258) 2004 Pan F., Egile C., Lipkin T., Li R. rli@hms.harvard.edu 23-MAY-2007: Contacted by JYOTI. Returned mail. in vitro In vitro pull down pull down western blot western blot Immuno blot Immuno blot Pan F., Egile C., Lipkin T., Li R. Figs 6A, 6B and 6C have been put in a separate entry (pan-2004-4) as the interactions they describe are shown to be indirect therefore should not export to a UniProt CC line. rli@hms.harvard.edu Accepted 2007-JUN-10 by JYOTI. 23-MAY-2007: Contacted by JYOTI. Returned mail. J. Biol. Chem. (0021-9258) 2004 ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. J. Biol. Chem. (0021-9258) 2004 Pan F., Egile C., Lipkin T., Li R. rli@hms.harvard.edu 23-MAY-2007: Contacted by JYOTI. Returned mail. in vitro In vitro pull down pull down western blot western blot Immuno blot Immuno blot Pan F., Egile C., Lipkin T., Li R. no This has been shown to be an indirect interaction - I have therefore separated it from pan-2004-2 to prevent UniProt CC export as only 2 proteins have been identified. rli@hms.harvard.edu Accepted 2007-JUN-10 by JYOTI. 23-MAY-2007: Contacted by JYOTI. Returned mail. J. Biol. Chem. (0021-9258) 2004 ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. ARPC1/Arc40 mediates the interaction of the actin-related protein 2 and 3 complex with Wiskott-Aldrich syndrome protein family activators. J. Biol. Chem. (0021-9258) 2004 Pan F., Egile C., Lipkin T., Li R. rli@hms.harvard.edu 23-MAY-2007: Contacted by JYOTI. Returned mail. yeasx Saccharomyces cerevisiae (Baker's yeast) Baker's yeast molecular sieving molecular sieving Gel Filtration Size Exclusion Chromatography Size Exclusion Chromatography Gel Filtration Sizing column western blot western blot Immuno blot Immuno blot Pan F., Egile C., Lipkin T., Li R. rli@hms.harvard.edu Accepted 2007-JUN-10 by JYOTI. 23-MAY-2007: Contacted by JYOTI. Returned mail. J. Biol. Chem. (0021-9258) 2004 arp3_yeast Actin-related protein 3 ARP3 ACT4 YJR065C J1760 Actin-like protein ARP3 protein protein yeast Saccharomyces cerevisiae Baker's yeast MSYLNNPAVVMDNGTGLTKLGFAGNDSPSWVFPTAIATAAPSNTKKSSGVGAPSAVSNEASYFGNSTSATNFNGATGGLLSNNLSGKRGTEDLDFYIGNEALVASQGPSYSLSYPIRHGQVENWDHMERFWENSIFKYLRTEPEDHFFLLTEPPLNPPENREQVAEIFFESFNCAGLYIAVQAVLALAASWTSSKVTDRSLTGTVIDSGDGVTHVIPVAEGYVIGSAIKNIPIAGRDITLFIQSLLRERGEADTSLRTAEKIKQEYCYVCPDIVKEFNKFDKDPSKFAQFVVENQEKTRRKVVDIGYERFLAPEIFFNPEIASSDFLTPLPTVVDQTIQACPIDVRKGLYNNIVLSGGSTMFKDFGRRLQRDLKSIVNNRIAQSELLSGTKSTGVDVSVISHRKQRNAVWFGGSLLAQTAEFKGYCHTKKDYEEYGPEIVRNFSLFNMV 5BBD87E83F476E9F 5BBD87E83F476E9F arpc3_yeast Actin-related protein 2/3 complex subunit 3 ARC18 YLR370C L8039.15 Arp2/3 complex 21 kDa subunit protein protein yeast Saccharomyces cerevisiae Baker's yeast MPAYHSTFPVDPNTDRMVGNFALLPLNTKFRGPAYPSNSDYDIIDECLDLFRANSFFKNFEIKSPADRVLIYGILFINDCLAHLKITTSFNEAVKVLTNVALDNFTLPGTPGFPLNNVYQVPVQDHNSMDLLKTYIQQFRQELAMRLLERVYSSTDSKEYPSKFWLAFTRRRFMNKSL 456EABC2B9CC4860 456EABC2B9CC4860 arp2_yeast Actin-related protein 2 ACT2 YDL029W D2778 ARP2 Actin-like protein ARP2 protein protein yeast Saccharomyces cerevisiae Baker's yeast MDPHNPIVLDQGTGFVKIGRAGENFPDYTFPSIVGRPILRAEERASVATPLKDIMIGDEASEVRSYLQISYPMENGIIKNWTDMELLWDYAFFEQMKLPSTSNGKILLTEPPMNPLKNREKMCEVMFEKYDFGGVYVAIQAVLALYAQGLSSGVVVDSGDGVTHIVPVYESVVLSHLTRRLDVAGRDVTRHLIDLLSRRGYAFNRTADFETVRQIKEKLCYVSYDLDLDTKLARETTALVESYELPDGRTIKVGQERFEAPECLFQPGLVDVEQPGVGELLFNTVQSADVDIRSSLYKAIVLSGGSSMYPGLPSRLEKELKQLWFSRVLHNDPSRLDKFKVRIEDPPRRKHMVFIGGAVLASIMADKDHMWLSKQEWQESGPSAMTKFGPR 4C9E8952B477A1B9 4C9E8952B477A1B9 myo5_yeast Myosin-5 MYO5 YMR109W YM9718.08 Class I unconventional myosin MYO5 Type I myosin MYO5 Actin-dependent myosin-I MYO5 protein protein yeast Saccharomyces cerevisiae Baker's yeast MAILKRGARKKVHQEPAKRSANIKKATFDSSKKKEVGVSDLTLLSKISDEAINENLKKRFLNATIYTYIGHVLISVNPFRDLGIYTDAVMNEYKGKNRLEVPPHVFAIAESMYYNMKSYNENQCVIISGESGAGKTEAAKRIMQYIAAASSTHTESIGKIKDMVLATNPLLESFGCAKTLRNNNSSRHGKYLEIKFNNQFEPCAGNITNYLLEKQRVVSQIKNERNFHIFYQFTKGASDAYRQTFGVQKPEQYVYTAAAGCISAETIDDLQDYQETLKAMRVIGLGQEEQDQIFRMLAAILWIGNVSFIENEEGNAQVRDTSVTDFVAYLLQIDSQLLIKSLVERIMETNHGMKRGSVYHVPLNIVQADAVRDALAKAIYNNLFDWIVSRVNKSLQAFPGAEKSIGILDIYGFEIFEHNSFEQICINYVNEKLQQIFIQLTLKSEQETYEREKIQWTPIKYFDNKVVCDLIEARRPPGIFAAMNDSVATAHADSNAADQAFAQRLNLFTTNPHFDLRSNKFVIKHYAGDVTYDIDGITDKNKDQLQKDLVELIGTTTNTFLATIFPDTVDRESKRRPPTAGDKIIKSANDLVETLSKAQPSYIRTIKPNETKSPNDYDDRQVLHQIKYLGLQENVRIRRAGFAYRQVFEKFVERFYLLSPHCSYAGDYTWQGDTLDAVKYILQDSSIPQQEYQLGVTSVFIKTPETLFALEHMRDRYWHNMAARIQRAWRRFLQRRIDAATKIQRTIRERKEGNKYEKLRDYGTKVLGGRKERRSMSLLGYRAFMGDYLSCNESKSKGAYIKRQVSIKEKVIFSIHGEALHTKFGRSAQRLKKTFLLTPTTLYIVGQTLVQNAMTYTQDYKIDVRNIQAVSLTNLQDDWVAIKLASSGQPDPLINTYFKTELITHLKRLNDKIQIKIGSAIEYQKKPGKLHSVKCQINESAPKYGDIYKSSTISVRRGNPPNSQVHKKPRKKSSISSGYHASSSQATRRPVSIAAAQHVPTAPASRHSKKPAPPPPGMQNKAATRRSVPNPASTLTASQSNARPSPPTAATRATPAATPAAAAMGSGRQANIPPPPPPPPPSSKPKEPMFEAAYDFPGSGSPSELPLKKGDVIYITREEPSGWSLGKLLDGSKEGWVPTAYMKPHSGNNNIPTPPQNRDVPKPVLNSVQHDNTSANVIPAAAQASLGDGLANALAARANKMRLESDDEEANEDEEEDDW DFFB9EC16B61CD29 DFFB9EC16B61CD29 arpc5_yeast Actin-related protein 2/3 complex subunit 5 ARC15 Arp2/3 complex 16 kDa subunit YIL062C protein protein yeast Saccharomyces cerevisiae Baker's yeast MEADWRRIDIDAFDPESGRLTAADLVPPYETTVTLQELQPRMNQLRSLATSGDSLGAVQLLTTDPPYSADAPTKEQYFKSVLEALTQVRQADIGNVIKNLSDSQRDVLVKYLYKGMSVPQGQKQGGVLLAWLERITQVSGVTPIVHYISDRRTV 10E4DAF0F0801B02 10E4DAF0F0801B02 las17_yeast Proline-rich protein LAS17 LAS17 YOR181W protein protein yeast Saccharomyces cerevisiae Baker's yeast MGLLNSSDKEIIKRALPKASNKIIDVTVARLYIAYPDKNEWQYTGLSGALALVDDLVGNTFFLKLVDINGHRGVIWDQELYVNFEYYQDRTFFHTFEMEECFAGLLFVDINEASHFLKRVQKRERYANRKTLLNKNAVALTKKVREEQKSQVVHGPRGESLIDNQRKRYNYEDVDTIPTTKHKAPPPPPPTAETFDSDQTSSFSDINSTTASAPTTPAPALPPASPEVRKEETHPKHSLPPLPNQFAPLPDPPQHNSPPQNNAPSQPQSNPFPFPIPEIPSTQSATNPFPFPVPQQQFNQAPSMGIPQQNRPLPQLPNRNNRPVPPPPPMRTTTEGSGVRLPAPPPPPRRGPAPPPPPHRHVTSNTLNSAGGNSLLPQATGRRGPAPPPPPRASRPTPNVTMQQNPQQYNNSNRPFGYQTNSNMSSPPPPPVTTFNTLTPQMTAATGQPAVPLPQNTQAPSQATNVPVAPPPPPASLGQSQIPQSAPSAPIPPTLPSTTSAAPPPPPAFLTQQPQSGGAPAPPPPPQMPATSTSGGGSFAETTGDAGRDALLASIRGAGGIGALRKVDKSQLDKPSVLLQEARGESASPPAAAGNGGTPGGPPASLADALAAALNKRKTKVGAHDDMDNGDDW 4488355563AA2645 4488355563AA2645 arpc1_yeast Actin-related protein 2/3 complex subunit 1 ARC40 YBR234C YBR1532 Arp2/3 complex 41 kDa subunit p41-ARC protein protein yeast Saccharomyces cerevisiae Baker's yeast MSFSNSKDKSVVAVYKLVKAPIYSHCFSQDKSILAVTCETDCLVYRVSNNTPPVLFATLKDHDKTITAVDISIHGRIVTCSQDRNAYVWEPLSDGTYKPTLVLLRINRAATSVTWAPNGYKFAVGSSARIIAVCYYEHENNWWVSKHIKKPIKSTINCLSWHANGVLLAAGGTDGFMRVFSGFIKGLDSKESVAGSPWGQKFPFGCLIREWYQGSYIHDVEWRSQMERIAYVAHDGTLNVVDYQSPVQSVNAPEGLPYRSLVWINDHEIVCGGYSCHPVLFSEASEGWKFAKNLDKSDNNKSSALTASGNTDELSGNNDESSTFGISALRKFKELDLKGKVSTDVQESAHENAIVELRPFAESNGQITQVSSCGLDGKIVIYTI D75C6BB8EC35EEDF D75C6BB8EC35EEDF wasl_human Neural Wiskott-Aldrich syndrome protein WASL protein protein human Homo sapiens Human MSSVQQQPPPPRRVTNVGSLLLTPQENESLFTFLGKKCVTMSSAVVQLYAADRNCMWSKKCSGVACLVKDNPQRSYFLRIFDIKDGKLLWEQELYNNFVYNSPRGYFHTFAGDTCQVALNFANEEEAKKFRKAVTDLLGRRQRKSEKRRDPPNGPNLPMATVDIKNPEITTNRFYGPQVNNISHTKEKKKGKAKKKRLTKADIGTPSNFQHIGHVGWDPNTGFDLNNLDPELKNLFDMCGISEAQLKDRETSKVIYDFIEKTGGVEAVKNELRRQAPPPPPPSRGGPPPPPPPPHNSGPPPPPARGRGAPPPPPSRAPTAAPPPPPPSRPSVAVPPPPPNRMYPPPPPALPSSAPSGPPPPPPSVLGVGPVAPPPPPPPPPPPGPPPPPGLPSDGDHQVPTTAGNKAALLDQIREGAQLKKVEQNSRPVSCSGRDALLDQIRQGIQLKSVADGQESTPPTPAPTSGIVGALMEVMQKRSKAIHSSDEDEDEDDEEDFEDDDEWED DIP protein O00401 original sequence version: 55 DIP protein O00401 original sequence version: 147 DIP protein O00401 original sequence version: 150 DIP protein O00401 original sequence version: 136 DIP protein O00401 original sequence version: 138 DIP protein O00401 original sequence version: 125 DIP protein O00401 original sequence version: 112 DIP protein O00401 original sequence version: 126 B5895C6055E23049 arp3-arc40-1 1 11 unspecified role unspecified role prey prey 5 unspecified role unspecified role bait bait region tap tagged calmodulin binding peptide plus protein a tag CBP-ProtA tagged CBP-ProtA tagged tap tagged undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined physical association physical association Here we first showed by mass spectrometry and gel filtration that Arc40 is indeed a component of purified yeast Arp2/3 complex but has a strong tendency to form high molecular weight species when analyzed by SDS-PAGE. 1 las17-arc40-1 2 11 unspecified role unspecified role prey prey region his tag his tag Hexa-His-tag 6-His-tag Histidine-tag Hexa-His-tag Histidine-tag 6-His-tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined region ha tag ha tag YPYDVPDYA epitope tag YPYDVPDYA epitope tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined spofr-sf_9 Spodoptera frugiperda insect cells Fall armyworm sf_9 insect cells Derived from pupal ovarian tissue of the fall armyworm Cloned from the parent cell line, IPLB-SF-21-AE (SF-21) derived from immature ovaries of fall armyworm Spodoptera frugiperda pupae cells are susceptible to Baculovirus infection 10 unspecified role unspecified role bait bait vca region sufficient to bind sufficient binding region sufficient to bind deletion analysis deletion analysis undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined region gst tag glutathione s tranferase tag glutathione S-tranferase tag glutathione S-tranferase tag gst tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined ecoli Escherichia coli (strain K12) physical association physical association To test this hypothesis, recombinant baculovirus-expressed His6-HA-tagged Arc40 was used to test the interaction with GST-VCA from Bee1 and N-WASP and CA from yeast Myo5. Purified VCA and CA fragments were cross-linked to Affi-Gel beads and tested for interaction with purified Arc40 by bead pull-down assays 3A Bait protein: Bee1; arc40-myo5-1 2 8 unspecified role unspecified role bait bait region gst tag glutathione s tranferase tag glutathione S-tranferase tag glutathione S-tranferase tag gst tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined ca region sufficient to bind sufficient binding region sufficient to bind deletion analysis deletion analysis undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined ecoli Escherichia coli (strain K12) 11 unspecified role unspecified role prey prey region his tag his tag Hexa-His-tag 6-His-tag Histidine-tag Hexa-His-tag Histidine-tag 6-His-tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined region ha tag ha tag YPYDVPDYA epitope tag YPYDVPDYA epitope tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined spofr-sf_9 Spodoptera frugiperda insect cells Fall armyworm sf_9 insect cells Derived from pupal ovarian tissue of the fall armyworm Cloned from the parent cell line, IPLB-SF-21-AE (SF-21) derived from immature ovaries of fall armyworm Spodoptera frugiperda pupae cells are susceptible to Baculovirus infection physical association physical association To test this hypothesis, recombinant baculovirus-expressed His6-HA-tagged Arc40 was used to test the interaction with GST-VCA from Bee1 and N-WASP and CA from yeast Myo5. Purified VCA and CA fragments were cross-linked to Affi-Gel beads and tested for interaction with purified Arc40 by bead pull-down assays 3A arc40-wsp-1 2 12 unspecified role unspecified role bait bait O00401:p.Trp503Ala mutation decreasing mutation decreasing interaction hotspot hotspot mutation decreasing mutation analysis mutation analysis certain certain sequence position certain certain certain sequence position certain W A Thu Jul 07 12:16:53 BST 2016 This feature has been corrected as a result of our quality control procedures. The original label was trp503ala Wed May 02 17:32:14 BST 2018 This feature has been corrected as a result of our quality control procedures. The original label was 'trp503ala' Tue Jun 30 18:41:19 BST 2020 This feature has been corrected as a result of our quality control procedures. The original label was 'p.Trp503Ala' region gst tag glutathione s tranferase tag glutathione S-tranferase tag glutathione S-tranferase tag gst tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined vca region sufficient to bind sufficient binding region sufficient to bind deletion analysis deletion analysis range range range range ecoli Escherichia coli (strain K12) 11 unspecified role unspecified role prey prey region his tag his tag Hexa-His-tag 6-His-tag Histidine-tag Hexa-His-tag Histidine-tag 6-His-tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined region ha tag ha tag YPYDVPDYA epitope tag YPYDVPDYA epitope tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined spofr-sf_9 Spodoptera frugiperda insect cells Fall armyworm sf_9 insect cells Derived from pupal ovarian tissue of the fall armyworm Cloned from the parent cell line, IPLB-SF-21-AE (SF-21) derived from immature ovaries of fall armyworm Spodoptera frugiperda pupae cells are susceptible to Baculovirus infection physical association physical association To test this hypothesis, recombinant baculovirus-expressed His6-HA-tagged Arc40 was used to test the interaction with GST-VCA from Bee1 and N-WASP and CA from yeast Myo5. Purified VCA and CA fragments were cross-linked to Affi-Gel beads and tested for interaction with purified Arc40 by bead pull-down assays 3A, 3B arp3-wsp-1 3 5 unspecified role unspecified role prey prey yeasx Saccharomyces cerevisiae (Baker's yeast) Baker's yeast 12 unspecified role unspecified role bait bait O00401:p.Trp503Ala mutation decreasing mutation decreasing interaction hotspot hotspot mutation decreasing mutation analysis mutation analysis certain certain sequence position certain certain certain sequence position certain W A Thu Jul 07 12:16:52 BST 2016 This feature has been corrected as a result of our quality control procedures. The original label was trp503ala Wed May 02 19:11:47 BST 2018 This feature has been corrected as a result of our quality control procedures. The original label was 'trp503ala' Tue Jun 30 16:07:31 BST 2020 This feature has been corrected as a result of our quality control procedures. The original label was 'p.Trp503Ala' region gst tag glutathione s tranferase tag glutathione S-tranferase tag glutathione S-tranferase tag gst tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined vca region sufficient to bind sufficient binding region sufficient to bind deletion analysis deletion analysis range range range range ecoli Escherichia coli (strain K12) physical association physical association For binding Arp2/3 complex from yeast extract, 5 �l of GST-VCA beads were mixed with variable amounts of high speed extracts or purified Arp2/3 complex in a total volume of 200 �l. Kd was determined as described previously 3A,6A WASP1 incubated with entire isolated Arp2/3 complex but only Arp3 identified by western blot. Isolation of the complex from Arc40 deficient cells indicated that loss of Arc40 strongly reduced the affinity of VCA with the Arp2/3 complex. The use of Arp2 deficient cells suggested that lack of Arp2 had only a slight effect on the interaction between Arp2/3 complex with VCA and that that ARPC1/Arc40 mediates a major interaction between the Arp2/3 complex and VCA. arp2-arp3-2 4 9 unspecified role unspecified role neutral component neutral component 6 unspecified role unspecified role neutral component neutral component 5 unspecified role unspecified role neutral component neutral component 7 unspecified role unspecified role neutral component neutral component physical association physical association Yeast extracts were analyzed on a SE1000 gel filtration column, and 0.5-ml fractions were collected. Every other fraction of fractions 15�37 were resolved by 12.5% SDS-PAGE and immunoblotted using antibodies against yeast Arp2, Arp3, Arc18 (ARPC3), and Arc15 (ARPC5). 5 Complexes forms in strains in which Arc40 has been deleted, but Arp2 is less strongly associated within it. arp2-wsp-2 3 12 unspecified role unspecified role bait bait O00401:p.Trp503Ala mutation decreasing mutation decreasing interaction hotspot hotspot mutation decreasing mutation analysis mutation analysis certain certain sequence position certain certain certain sequence position certain W A Thu Jul 07 12:18:21 BST 2016 This feature has been corrected as a result of our quality control procedures. The original label was trp503ala Wed May 02 19:25:44 BST 2018 This feature has been corrected as a result of our quality control procedures. The original label was 'trp503ala' Tue Jun 30 18:53:51 BST 2020 This feature has been corrected as a result of our quality control procedures. The original label was 'p.Trp503Ala' region gst tag glutathione s tranferase tag glutathione S-tranferase tag glutathione S-tranferase tag gst tag undetermined undetermined sequence position undetermined undetermined undetermined sequence position undetermined vca region sufficient to bind sufficient binding region sufficient to bind deletion analysis deletion analysis range range range range ecoli Escherichia coli (strain K12) 7 unspecified role unspecified role prey prey yeasx Saccharomyces cerevisiae (Baker's yeast) Baker's yeast physical association physical association yeast extracts prepared from wild-type and {Delta}arc40 strains were incubated with VCA beads, and unbound (Sup) and bound (Pellet) Arp2/3 complex was detected by immunoblot analysis using the anti-Arp2 antibody. 6B, 6C WASP1 incubated with entire isolated Arp2/3 complex but only Arp2 identified by western blot. Isolation of the complex from Arc40 deficient cells indicated that loss of Arc40 strongly reduced the affinity of VCA with the Arp2/3 complex. The use of Arp2 deficient cells suggested that lack of Arp2 and Arp3 had only a slight effect on the interaction between Arp2/3 complex with VCA and that that ARPC1/Arc40 mediates a major interaction between the Arp2/3 complex and VCA.