a deficiency of liver phosphorylase kinase, causing a lack of active glycogen phosphorylase, although total phosphorylase is normal. The intravenous injection of glucagon caused a rapid activation of cyclic AMP-dependent protein kinase in the liver, but no increase in either phosphorylase kinase or phosphorylase a activity. Although total glycogen synthase activity in the livers of affected rat...

The PHO85 gene of Saccharomyces cerevisiae encodes a cyclin-dependent protein kinase that can interact with 10 different cyclins (Pcls). In conjunction with Pcl8p and Pcl10p, Pho85p phosphorylates and regulates glycogen synthase. Respiratory-deficient strains, such as coq3 mutants, have reduced glycogen stores and contain hyperphosphorylated and inactive glycogen synthase. We show here that pho...

Addition of micromolar concentrations of the adenosine derivative 5-iodotubercidin (Itu) initiates glycogen synthesis in isolated hepatocytes by causing inactivation of phosphorylase and activation of glycogen synthase [Flückiger-Isler and Walter (1993) Biochem. J. 292, 85-91]. We report here that Itu also antagonizes the effects of saturating concentrations of glucagon and vasopressin on these...

Glycogen, a stored form of glucose, is an important energy for aquatic shellfish, contributing to the flavor and quality oyster. The glycogen synthase (GYS) kinase 3β (GSK3β) are two major enzymes in glycogenesis. However, information genes Jinjiang oyster Crassostrea ariakensis remains limited. In this study, we identified GYS GSK3β further explored their function synthesis C. ariakensis. were...

In Saccharomyces cerevisiae, PHO85 encodes a cyclin-dependent protein kinase (Cdk) with multiple roles in cell cycle and metabolic controls. In association with the cyclin Pho80, Pho85 controls acid phosphatase gene expression through phosphorylation of the transcription factor Pho4. Pho85 has also been implicated as a kinase that phosphorylates and negatively regulates glycogen synthase (Gsy2)...

Recent studies have suggested that abnormal regulation of protein phosphatase 2A (PP2A) is associated with Type 2 diabetes in rodent and human tissues. Results with cultured mouse myotubes support a mechanism for palmitate activation of PP2A, leading to activation of glycogen synthase kinase 3. Phosphorylation and inactivation of glycogen synthase by glycogen synthase kinase 3 could be the mech...

A protein kinase, able to phosphorylate casein, phosvitin, and glycogen synthase, was purified approximately 9000-fold from rabbit liver, and appeared analogous to an enzyme studied by Itarte and Huang (Itarte, E., and Huang, K.-P. (1979) J. Biol. Chem. 254, 4052-4057). This enzyme, designated here casein kinase-1, was shown to be a distinct glycogen synthase kinase and in particular to be diff...

Insulin produces an increase in the conversion of the D form (glucose-6-P dependent) of liver glycogen synthase to the Z form (glucose-6-P independent) when injected intravenously into fed alloxan diabetic rats. Insulin activates glycogen synthase previously inactivated by glucagon in isolated perfused livers from normal rats, while increasing [14C]glucose incorporation into glycogen and decrea...

We have investigated the signalling pathways involved in the stimulation of glycogen and fatty acid synthesis by insulin in rat fat cells using wortmannin, an inhibitor of phosphatidylinositol 3-kinase, and rapamycin, which blocks activation of p70 ribosomal S6 protein kinase (p70S6K). Insulin produced a decrease in the activity of glycogen synthase kinase-3 which is likely to be important in t...