. "Reviewed: Heldin, CH, 2008-02-12 09:44:02"^^ . "Edited: Orlic-Milacic, Marija, 2011-08-25"^^ . "Authored: Castagnoli, L, 2006-10-10 13:09:34"^^ . "The Src homology 2 (SH2) domain of the phosphatidylinositol 3-kinase (PIK3) regulatory subunit (PIK3R1, i.e. PI3Kp85) binds to GAB1 in a phosphorylation-independent manner. GAB1 serves as a docking protein which recruits a number of downstream signalling proteins. PIK3R1 can bind to either GAB1 or phosphorylated GAB1."^^ . . . . . . "Binding of PIK3 regulatory alpha subunit to GRB2:GAB1"^^ . . . .