Overview:

GRB2 is an adaptor protein that is the homolog of the Sem5 gene of C. elegans and Drk gene of Drosophila. GRB2 protein contains one SH2 domain and two SH3 domains and plays a role in growth factor-mediated signal transduction. GRB2 forms a complex with activated EGFR and the RAS-specific guanine nucleotide exchange factor SOS1 thereby mediating the growth factor-induced activation of RAS (1). GRB2 has been implicated in growth factor regulation of the cytoskeleton and DNA synthesis. DAB2 also binds to GRB2 and competes with SOS for GRB2 binding. GRB2 interacts with the hepatitis C virus nonstructural 5A (NS5A) protein and inhibits the activation of ERK1 and ERK2 by EGF (2).

Gene Aliases:

ASH, Grb3-3, MST084, MSTP084, EGFRBP-GRB2

Genbank Number:

NM_002086

References:

1. Lowenstein, E. J. et al: The SH2 and SH3 domain-containing protein GRB2 links receptor tyrosine kinases to ras signaling. Cell 70: 431-442, 1992.

2. Tan, S.-L. et al: NS5A, a nonstructural protein of hepatitis C virus, binds growth factor receptor-bound protein 2 adaptor protein in a Src homology 3 domain/ligand-dependent manner and perturbs mitogenic signaling. Proc. Nat. Acad. Sci. 96: 5533-5538, 1999.