Oxytocin inactivates and phosphorylates rat hepatocyte glycogen synthase.
Biochem J
; 261(3): 827-30, 1989 Aug 01.
Article
em En
| MEDLINE
| ID: mdl-2508622
ABSTRACT
Incubation of isolated rat hepatocytes with oxytocin produces a time- and dose-dependent inactivation of glycogen synthase. Such inactivation is associated with an increase in the phosphorylation state of the 88 kDa subunit of the enzyme, as observed after electrophoretic analysis of the 32P-labelled enzyme isolated by immunoprecipitation from cells incubated with [32P]phosphate. CNBr cleavage of the immunoprecipitated glycogen synthase showed that multiple sites were phosphorylated after exposure of the cells to the hormone. The effect of oxytocin on hepatocyte glycogen synthase activity was not observed in the absence of extracellular Ca2+. Inactivation of glycogen synthase by oxytocin was partially abolished in the presence of insulin. These results indicate that the effects of oxytocin on glycogen synthase from rat hepatocytes are similar to those observed for other Ca2+-mediated glycogenolytic hormones, such as vasopressin.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Limite:
Animals
Idioma:
En
Ano de publicação:
1989
Tipo de documento:
Article