Phosphoinositide 3-kinase is activated by phosphopeptides that bind to the SH2 domains of the 85-kDa subunit - Carpenter, CL; Auger, KR; Chanudhuri, M; Yoakim, M; Schaffhausen, B; Shoelson, S; Cantley, LC (J Biol Chem, 1993)