EC Number   |
Application |
Reference |
|---|
    2.4.1.11 | medicine |
glycogen synthase activity correlates inversely with phosphorylation of glycogen synthase sites 2 + 2a and 3a. Insulin significantly decreases 2 + 2a phosphorylation in lean subjects only and induces a larger dephosphorylation at site 3 in lean compared with obese subjects. The exaggerated insulin resistance in type 2 diabetes mellitus compared with obese subjects is not reflected by differences in site 3 phosphorylation but is accompanied by a significantly higher site 1b phosphorylation during insulin stimulation. Hyperphosphorylation of another Ca2/calmodulin-dependent kinase-II target, phospholamban-Thr17, is also evident in type 2 diabetes mellitus. Dephosphorylation of glycogen synthase by phosphatase treatment fully restores glycogen synthase activity in all groups |
704825 |
| 2.4.1.11 | medicine |
in patients with polycystic ovary syndrome, reduced insulin-mediated glucose disposal is associated with a lower insulin-stimulated glycogen synthase activity, explained by absent insulin-mediated dephosphorylation of glycogen synthase at the NH2-terminal sites 2 + 2a, whereas dephosphorylation at the COOH-terminal sites 3a + 3b is intact in polycystic ovary syndrome subjects. Insulin activation of glycogen synthase is dependent on dephosphorylation of sites 3a + 3b in women with polycystic ovary syndrome. No significant abnormalities in glycogen synthaseK-3 or -3 are found. Pioglitazone treatment improves insulin-stimulated glucose metabolism and glycogen synthase activity in polycystic ovary syndrome and restores the ability of insulin to dephosphorylate glycogen synthase at sites 2 and 2a |
704823 |
| 2.4.1.11 | medicine |
insulin, insiulin-like growth factor 1 and relaxin stimulate the enzymatic activity. In patients with type 1 diabetes glycogen synthase activity remains unchanged versus control, and insulin does not stimulate the enzyme activity. In patients with type 2 diabetes a significant decrease in glycogen synthase activity is accompanied by the decrease in the effect of peptides, giving the following order of their efficiency: insulin = IGF-1 > relaxin. In myometrium of pregnant women with gestational treated and untreated diabetes, glycogen synthase activity decreases, the effect of insulin is weaker, whereas the effects of relaxin and IGF-1 increase thus giving the following order of their efficiency: relaxin > IGF-1 > insulin. Insulin therapy of type 1 diabetes incompletely restores sensitivity of the enzymes to the peptide actions |
702190 |
| 2.4.1.11 | medicine |
mutation R243X has been identified in a patient with glycogen storage disease type 0, together with frameshift mutation 966_967delGA/insC introducing a stop codon 21 amino acids downstream from the site of the mutation and leading to loss of 51% of the C-terminal portion of the protein. Patient is heterozygous for the mutations and presents with fasting hypoglycemia and postprandial hyperglycemia |
702899 |
| 2.4.1.11 | medicine |
old compared to young rats maintained ad libitum on a standard diet have reduced glycogen synthase activity, lower muscle glycogen synthase protein levels, increased phosphorylation of glycogen synthase at site 3a with less activation in soleus muscle. Age-associated impairments in glycogen synthase protein and activation-phosphorylation are also shown in tibialis anterior muscle. There is an age-associated reduction in glycogen phosphorylase activity level in soleus, while brain/muscle isoforms of glycogen phosphorylase protein levels are higher. Calorie restriciton does not alter glycogen synthase or glycogen phosphatase activity/protein levels in young rats. Calorie restriction hinders age-related decreases in glycogen synthase activity/protein, unrelated to glycogen synthase mRNA levels, and glycogen synthase inactivation-phosphorylation |
703590 |
| 2.4.1.11 | medicine |
patient with muscle-specific glycogen synthase deficiency due to homozygous two base pair deletion in exon 2, c.162-163delAG. Mutation is predicted to result in a protein frameshift that alters the amino acid sequence after the mutation and terminates prematurely. Patient presents with abnormal mitochondrial ultrastructure and pre-ragged red fibres, predominance of type I oxidative fibres in the muscle and depletion of glycogen stores |
705759 |
| 2.4.1.11 | nutrition |
calorie restriciton does not alter glycogen synthase or glycogen phosphatase activity/protein levels in young rats. Calorie restriction hinders age-related decreases in glycogen synthase activity/protein, unrelated to glycogen synthase mRNA levels, and glycogen synthase inactivation-phosphorylation |
703590 |
