Insulin-dependent release of 5'-nucleotidase and alkaline phosphatase from liver plasma membranes.
Insulin treatment of isolated liver plasma membranes induced the release of 5'-nucleotidase and alkaline phosphatase. This effect was maximal at physiological hormone concentrations, being 36% and 17% for 5'-nucleotidase and alkaline phosphatase respectively, and was fully mimicked by the phosphatidylinositol specific phospholipase C (PI-PLC), thus confirming the presence of a glycosylphosphatidylinositol anchoring-system for these exofacial enzymatic proteins. The complete inhibition of insulin dependent enzyme release by neomycin is strongly supportive of an involvement of membrane-located PI-PLC activity. In addition, the insulin-like effect on enzyme release induced by the GTP non-hydrolysable analog, GTP-gamma-S, and its sensitivity to the pertussis toxin are in favour of a mediatory role exerted by the G proteins system, in the transduction of some actions of insulin.
Incerpi
S
S
Department of Biology, University of Rome, Tor Vergata, Italy.
Baldini
P
P
Lo Bello
M
M
Luly
P
P
D015720:5'-Nucleotidase / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000378:metabolism; D017261:Glycosylphosphatidylinositols; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D007329:Insulin Antagonists; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009355:Neomycin / Q000494:pharmacology; D037342:Pertussis Toxin; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D010716:Phosphatidylinositols / Q000032:analysis*; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology; D011134:Polysaccharides / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D010566:Virulence Factors, Bordetella
D017261:Glycosylphosphatidylinositols; D007328:Insulin; D007329:Insulin Antagonists; D010716:Phosphatidylinositols; D011134:Polysaccharides; D010566:Virulence Factors, Bordetella; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D037342:Pertussis Toxin; D000469:Alkaline Phosphatase; D015720:5'-Nucleotidase; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D019204:GTP-Binding Proteins; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D009355:Neomycin