GRB2 Associated Binding Protein 1 (GAB1)

GAB1 is a member of the IRS1-like multisubstrate docking protein family. It is an important mediator of branching tubulogenesis and plays a central role in cellular growth response, transformation and apoptosis. Two transcript variants encoding different isoforms have been found for this gene.The GAB1 protein shares amino acid sequence homology and several structural features with the IRS1 protein . The greatest homology (31% identity and 44% similarity) is in the pleckstrin homology domain in the N terminus of both proteins. The distal two-thirds of both proteins have numerous predicted serine/threonine phosphorylation sites and several potential phosphotyrosine sites, suggesting that, like IRS1, GAB1 is a docking protein.