Stimulation by mammalian insulin of glycogen metabolism in a wall-less strain of Neurospora crassa.
Addition of bovine insulin to cells of the wall-less variant FGSC4761 of Neurospora crassa ("slime") produced several significant effects on glycogen metabolism. 1) Intracellular levels of the glycogen precursor UDP-glucose decreased 17-18% (P less than 0.01) within 30 min of insulin addition. 2) Cells grown with insulin possessed 40% more glycogen than did control cells. 3) The incorporation of 14C-labeled glucose into glycogen increased 41% after 30-min treatment with 100 nM bovine insulin (P less than 0.01). 4) Insulin treatment of the cells caused activation of the enzyme glycogen synthase from a glucose-6-phosphate-dependent form to an independent form. Half-maximum activation occurred with 2 nM insulin. These are similar to insulin-induced effects in some mammalian cells. In contrast, no insulin-induced effect on glucose transport could be demonstrated in these cells.
D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D006003:Glycogen / Q000378:metabolism*; D006006:Glycogen Synthase / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D009491:Neurospora / Q000187:drug effects*; D009492:Neurospora crassa / Q000187:drug effects* / Q000378:metabolism; D014532:Uridine Diphosphate Glucose / Q000378:metabolism
D007328:Insulin; D006003:Glycogen; D006006:Glycogen Synthase; D014532:Uridine Diphosphate Glucose