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Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 10 GRB10, also termed insulin receptor-binding protein Grb-IR, is a multi-domain cytoplasmic adaptor protein that binds to the insulin-like growth factor 1 receptor (IGF-1R) and inhibits insulin signaling. Grb10 and its related family members Grb7 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm. Grb14 binds to both GTPase-defective mutant Rab5 as well as CNGA1, whereas Grb10 binds only to GTP-bound form of active Rab5.
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