Phosphatidylinositol 3-kinase: Structure and expression of the 110 kd catalytic subunit

作者：I. Hiles, Masayuki Otsu, Stefano Volinia, Michael Fry, Ivan T. Gout, Ritu Dhand, George Panayotou, Fernanda Ruiz‐Larrea, Andrew R. Thompson, Nicholas F. Totty, J.Justin Hsuan, Sara A. Courtneidge, Peter J. Parker, Michael D. Waterfield · 发表于：Cell · 年份：1992 · DOI：10.1016/0092-8674(92)90166-a · 被引用次数：697 · 研究领域：Protein Kinase Regulation and GTPase Signaling、Cellular transport and secretion、Viral Infectious Diseases and Gene Expression in Insects

Purified bovine brain phosphatidylinositol 3-kinase (Pl3-kinase) is composed of 85 kd and 110 kd subunits. The 85 kd subunit (p85 alpha) lacks Pl3-kinase activity and acts as an adaptor, coupling the 110 kd subunit (p110) to activated protein tyrosine kinases. Here the characterization of the p110 subunit is presented. cDNA cloning reveals p110 to be a 1068 aa protein related to Vps34p, a S. cerevisiae protein involved in the sorting of proteins to the vacuole. p110 expressed in insect cells possesses Pl3-kinase activity and associates with p85 alpha into an active p85 alpha-p110 complex that binds the activated colony-stimulating factor 1 receptor. p110 expressed in COS-1 cells is catalytically active only when complexed with p85 alpha.