TY - JOUR
T1 - The activity of the GTPase-activating protein CdGAP is regulated by the endocytic protein intersectin
AU - Jenna, Sarah
AU - Hussain, Natasha K.
AU - Danek, Eric I.
AU - Triki, Ibtissem
AU - Wasiak, Sylwia
AU - McPherson, Peter S.
AU - Lamarche-Vane, Nathalie
PY - 2002/2/22
Y1 - 2002/2/22
N2 - The Rho GTPases RhoA, Rac1, and Cdc42 play a major role in regulating the reorganization of the actin cytoskeleton. We recently identified CdGAP, a novel GTPase-activating protein with activity toward Rac1 and Cdc42. CdGAP consists of a N-terminal GAP domain, a central domain, and a C-terminal proline-rich domain. Here we show that through a subset of its Src homology 3 domains, the endocytic protein intersectin interacts with CdGAP. In platelet-derived growth factor-stimulated Swiss 3T3 cells, intersectin co-localizes with CdGAP and inhibits its GAP activity toward Rac1. Intersectin-Src homology 3 also inhibits CdGAP activity in GAP assays in vitro. Although the C-terminal prolinerich domain of CdGAP is required for the regulation of its GAP activity by intersectin both in vivo and in vitro, it is not necessary for CdGAP-intersectin interaction. Our data suggest that the central domain of CdGAP is required for CdGAP-intersectin interaction. Thus, we propose a model in which intersectin binding results in a change of CdGAP conformation involving the prolinerich domain that leads to the inhibition of its GAP activity. These observations provide the first demonstration of a direct regulation of RhoGAP activity through a protein-protein interaction and suggest a function for intersectin in Rac1 regulation and actin dynamics.
AB - The Rho GTPases RhoA, Rac1, and Cdc42 play a major role in regulating the reorganization of the actin cytoskeleton. We recently identified CdGAP, a novel GTPase-activating protein with activity toward Rac1 and Cdc42. CdGAP consists of a N-terminal GAP domain, a central domain, and a C-terminal proline-rich domain. Here we show that through a subset of its Src homology 3 domains, the endocytic protein intersectin interacts with CdGAP. In platelet-derived growth factor-stimulated Swiss 3T3 cells, intersectin co-localizes with CdGAP and inhibits its GAP activity toward Rac1. Intersectin-Src homology 3 also inhibits CdGAP activity in GAP assays in vitro. Although the C-terminal prolinerich domain of CdGAP is required for the regulation of its GAP activity by intersectin both in vivo and in vitro, it is not necessary for CdGAP-intersectin interaction. Our data suggest that the central domain of CdGAP is required for CdGAP-intersectin interaction. Thus, we propose a model in which intersectin binding results in a change of CdGAP conformation involving the prolinerich domain that leads to the inhibition of its GAP activity. These observations provide the first demonstration of a direct regulation of RhoGAP activity through a protein-protein interaction and suggest a function for intersectin in Rac1 regulation and actin dynamics.
UR - http://www.scopus.com/inward/record.url?scp=0037155275&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037155275&partnerID=8YFLogxK
U2 - 10.1074/jbc.M105516200
DO - 10.1074/jbc.M105516200
M3 - Article
C2 - 11744688
AN - SCOPUS:0037155275
SN - 0021-9258
VL - 277
SP - 6366
EP - 6373
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 8
ER -