Structural and functional studies of the Ras-associating and pleckstrin-homology domains of Grb10 and Grb14.
Growth factor receptor-binding proteins Grb7, Grb10 and Grb14 are adaptor proteins containing a Ras-associating (RA) domain, a pleckstrin-homology (PH) domain, a family-specific BPS (between PH and SH2) region and a C-terminal Src-homology-2 domain. Previous structural studies showed that the Grb14 BPS region binds as a pseudosubstrate inhibitor in the tyrosine kinase domain of the insulin receptor to suppress insulin signaling. Here we report the crystal structure of the RA and PH domains of Grb10 at 2.6-A resolution. The structure reveals that these two domains, along with the intervening linker, form an integrated, dimeric structural unit. Biochemical studies demonstrated that Grb14 binds to activated Ras, which may serve as a timing mechanism for downregulation of insulin signaling. Our results illuminate the membrane-recruitment mechanisms not only of Grb7, Grb10 and Grb14 but also of MIG-10, Rap1-interacting adaptor molecule, lamellipodin and Pico, proteins involved in actin-cytoskeleton rearrangement that share a structurally related RA-PH tandem unit.
Depetris
Rafael S
RS
Structural Biology Program, Kimmel Center for Biology and Medicine of the Skirball Institute, and Department of Pharmacology, New York University School of Medicine, New York, New York, USA.
Wu
Jinhua
J
Hubbard
Stevan R
SR
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D051383:GRB10 Adaptor Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051382:GRB7 Adaptor Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D008958:Models, Molecular; D009154:Mutation; D010716:Phosphatidylinositols / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011972:Receptor, Insulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D018631:ras Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; C096358:GRB10 protein, human; C099655:GRB14 protein, human; C495955:GRB7 protein, human; D010716:Phosphatidylinositols; D051382:GRB7 Adaptor Protein; D051383:GRB10 Adaptor Protein; D011972:Receptor, Insulin; D018631:ras Proteins