A Ras-GTPase-activating protein SH3-domain-binding protein.
We report the purification of a Ras-GTPase-activating protein (GAP)-binding protein, G3BP, a ubiquitously expressed cytosolic 68-kDa protein that coimmunoprecipitates with GAP. G3BP physically associates with the SH3 domain of GAP, which previously had been shown to be essential for Ras signaling. The G3BP cDNA revealed that G3BP is a novel 466-amino-acid protein that shares several features with heterogeneous nuclear RNA-binding proteins, including ribonucleoprotein (RNP) motifs RNP1 and RNP2, an RG-rich domain, and acidic sequences. Recombinant G3BP binds effectively to the GAP SH3 domain G3BP coimmunoprecipitates with GAP only when cells are in a proliferating state, suggesting a recruitment of a GAP-G3BP complex when Ras is in its activated conformation.
Parker
F
F
Gene Medicine Department, Rhône-Poulenc Rorer, Centre de Recherche de Vitry-Alfortville, Vitry Sur Seine, France.
Maurier
F
F
Delumeau
I
I
Duchesne
M
M
Faucher
D
D
Debussche
L
L
Dugue
A
A
Schweighoffer
F
F
Tocque
B
B
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D003600:Cytosol / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D020690:GTPase-Activating Proteins; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D011233:Precipitin Tests; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D020703:ras GTPase-Activating Proteins; D018909:src Homology Domains
D018076:DNA, Complementary; D020690:GTPase-Activating Proteins; D011506:Proteins; D020703:ras GTPase-Activating Proteins