title: The WRP component of the WAVE-1 complex attenuates Rac-mediated signalling.
abstract: WAVE-1, which is also known as Scar, is a scaffolding protein that directs actin reorganization by relaying signals from the GTPase Rac to the Arp2/3 complex. Although the molecular details of WAVE activation by Rac have been described, the mechanisms by which these signals are terminated remain unknown. Here we have used tandem mass spectrometry to identify previously unknown components of the WAVE signalling network including WRP, a Rac-selective GTPase-activating protein. WRP binds directly to WAVE-1 through its Src homology domain 3 and specifically inhibits Rac function in vivo. Thus, we propose that WRP is a binding partner of WAVE-1 that functions as a signal termination factor for Rac.
authors.affiliation: Howard Hughes Medical Institute, Vollum Institute, 3181 Sam Jackson Park Road, Portland, Oregon 97239-3098, USA.
authors.forename: Scott H
authors.initials: SH
authors.lastname: Soderling
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: Binns
authors.forename: Gary A
authors.initials: GA
authors.lastname: Wayman
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Davee
authors.forename: Siew Hwa
authors.initials: SH
authors.lastname: Ong
authors.forename: Tony
authors.initials: T
authors.lastname: Pawson
authors.forename: John D
authors.initials: JD
authors.lastname: Scott
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D008840:Microfilament Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D016415:Sequence Alignment; D051300:Wiskott-Aldrich Syndrome Protein Family; D020744:rac GTP-Binding Proteins / Q000502:physiology*
chemical_list: D008840:Microfilament Proteins; D051300:Wiskott-Aldrich Syndrome Protein Family; D020744:rac GTP-Binding Proteins