Identification of Ser-1275 and Ser-1309 as autophosphorylation sites of the insulin receptor 1

Phosphorylation of Ser in Insulin Receptor Substrate-1 Blocks Interactions with the Insulin Receptor and Inhibits Insulin Action*

Serine phosphorylation of insulin receptor substrate-1 (IRS-1) inhibits insulin signal transduction in a variety of cell backgrounds, which might contribute to peripheral insulin resistance. However, because of the large number of potential phosphorylation sites, the mechanism of inhibition has been difficult to determine. One serine residue located near the phosphotyrosinebinding (PTB) domain ...

Phosphorylation of Human CTP Synthetase 1 by Protein Kinase C IDENTIFICATION OF Ser AND Thr AS MAJOR SITES OF PHOSPHORYLATION*

Phosphorylation of human CTP synthetase 1 by mammalian protein kinase C was examined. Using purified Escherichia coliexpressed CTP synthetase 1 as a substrate, protein kinase C activity was timeand dose-dependent and dependent on the concentrations of ATP and CTP synthetase 1. The protein kinase C phosphorylation of the recombinant enzyme was accompanied by a 95-fold increase in CTP synthetase ...

Identification of IRS-1 Ser-1101 as a target of S6K1 in nutrient- and obesity-induced insulin resistance.

S6K1 has emerged as a critical signaling component in the development of insulin resistance through phosphorylation and inhibition of IRS-1 function. This effect can be triggered directly by nutrients such as amino acids or by insulin through a homeostatic negative-feedback loop. However, the role of S6K1 in mediating IRS-1 phosphorylation in a physiological setting of nutrient overload is unre...

Ser - D 1

Characterization of recombinant skeletal muscle (Ser-2843) and cardiac muscle (Ser-2809) ryanodine receptor phosphorylation mutants.

Phosphorylation of the skeletal muscle (RyR1) and cardiac muscle (RyR2) ryanodine receptors has been reported to modulate channel activity. Abnormally high phosphorylation levels (hyperphosphorylation) at Ser-2843 in RyR1 and Ser-2809 in RyR2 and dissociation of FK506-binding proteins from the receptors have been implicated as one of the causes of altered calcium homeostasis observed during hum...