title: Activation induced by luteinizing hormone of type II protein kinase dependent on cyclic adenosine monophosphate and phosphorylation of soluble proteins in porcine granulosa cells.
abstract: The present experiments were designed to study whether exogenous LH could elicit acute cyclic AMP-mediated activation of cyclic AMP-dependent protein kinase and phosphorylation of cellular protein in intact porcine granulosa cells. Incubation of porcine granulosa cells (from 3 to 5 mm diameter follicles) with 2 microgram luteinizing hormone/ml (LH) caused a significant rise of cellular cyclic AMP content within 2 min of the addition of LH. The increase was dose-dependent and occurred between doses of 0.2 and 2.0 microgram LH/ml. Luteinizing hormone also caused a time- and dose-dependent dissociation of the type II cyclic AMP-dependent protein kinase isozyme in porcine granulosa cells. Luteinizing hormone (0.05--2 microgram/ml) significantly dissociated the cyclic AMP-dependent protein kinase between 2 and 30 min after stimulation. The protein kinase dissociation was a specific effect of LH and was not elicited by either adrenocorticotrophic hormone or prolactin. During the period of LH-induced protein kinase activation, several soluble granulosa cell proteins, ranging in molecular weights from about 43 000 to 99 000, became phosphorylated in a time-dpeendent and hormone-specific manner. The results suggest that cyclic AMP-mediated activation of granulosa cell type II cyclic AMP-dependent protein kinase may be a prerequisite in the short-term molecular action of LH leading to LH-specific phosphorylation of several soluble granulosa cell proteins of an as yet unidentified function.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000494:pharmacology*; D010766:Phosphorylation; D011374:Progesterone / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D013268:Stimulation, Chemical; D013347:Subcellular Fractions / Q000378:metabolism; D013552:Swine
chemical_list: D011506:Proteins; D011374:Progesterone; D007986:Luteinizing Hormone; D000242:Cyclic AMP; D011494:Protein Kinases