PI 3-kinase is a dual specificity enzyme: autoregulation by an intrinsic protein-serine kinase activity. - Dhand,R.; Hiles,I.; Panayotou,G.; Roche,S.; Fry,M.J.; Gout,I.; Totty,N.F.; Truong,O.; Vicendo,P.; Yonezawa,K. (Embo J, 1994)