[HTML][HTML] Regulation of Phosphatidylinositol 3′-kinase by tyrosyl phosphoproteins: full activation requires occupancy of Both SH2 domains in the 85-kDa regulatory …
T Rordorf-Nikolic, DJ Van Horn, D Chen… - Journal of Biological …, 1995 - ASBMB
Phosphatidylinositol 3′-kinase (PI 3′-kinase) is activated in insulin-stimulated cells by the
binding of the SH2 domains in its 85-kDa regulatory subunit to insulin receptor substrate-1
(IRS-1). We have previously shown that both tyrosyl-phosphorylated IRS-1 and mono-
phosphopeptides containing a single YXXM motif activate PI 3′-kinase in vitro. However,
activation by the mono-phosphopeptides was significantly less potent than activation by the
multiply phosphorylated IRS-1. We now show that the increased potency of PI 3′-kinase …
binding of the SH2 domains in its 85-kDa regulatory subunit to insulin receptor substrate-1
(IRS-1). We have previously shown that both tyrosyl-phosphorylated IRS-1 and mono-
phosphopeptides containing a single YXXM motif activate PI 3′-kinase in vitro. However,
activation by the mono-phosphopeptides was significantly less potent than activation by the
multiply phosphorylated IRS-1. We now show that the increased potency of PI 3′-kinase …