IEPA.d138.s327
Insulin-like signaling in yeast: modulation of protein phosphatase 2A, protein kinase A, cAMP-specific phosphodiesterase, and glycosyl-phosphatidylinositol-specific phospholipase C activities
IEPA.d138.s328
In addition, glycosyl-phosphatidylinositol-specific phospholipase C (GPI-PLC), which in isolated rat adipocytes is activated by insulin, was stimulated to up to 5-fold by glucose and 10-fold by glucose plus insulin in both yeast spheroplasts and intact cells leading to a concentration-dependent leftward shift of the glucose-response curve for activation of the GPI-PLC
IEPA.d138.s329
GPI-PLC was most pronouncedly stimulated by authentic human insulin compared to various insulin analogues and insulin-like growth factor I
IEPA.d138.s330
As the GPI-PLC reaction is rate limiting, the efficiency of the two-step anchor cleavage was significantly increased when insulin was present together with glucose as compared to glucose alone
IEPA.d138.s331
The insulin concentrations effective in modulating PP2A, PKA, cAMP-PDE, and GPI-PLC activities correlate well with those required for half-saturation of the specific binding sites as well as for stimulation of protein phosphorylation and glycogen accumulation
IEPA.d138.s332
The data suggest that mammalian insulin-sensitive cells and yeast share (part of) the key regulatory mechanism (consisting of PP2A, PKA, cAMP-PDE, and GPI-PLC) involved in the transduction of the insulin signal from the respective receptor systems to glycogen synthase and phosphorylase