title: Cyclic AMP-dependent protein kinase in mitochondria and cytosol from different-sized follicles and corpora lutea of porcine ovaries.
abstract: cAMP-dependent protein kinase was examined in mitochondria and cytosol prepared from different-sized antral follicles and corpora lutea of porcine ovaries. In all ovarian tissues examined except small follicles, protein kinase-specific activity was significantly higher in mitochondria than in cytosol, with the highest to lowest activities being found in medium (4-6 mm) follicles, large (7-12 mm) follicles, corpora lutea, and small (1-3 mm) follicles, respectively. Using the photoaffinity analogue [32P]8-N3cAMP, two major cAMP binding proteins with Mr = 47,000 (the apparent regulatory subunit of protein kinase Type I) and 54,000-56,000 (Type II) were found in all ovarian preparations. Type II was predominant in the cytosol of all ovarian samples, with the cytosolic Type I to Type II ratio increasing from approximately 0.05 in small and medium follicles top approximately 0.20 in large follicles and corpora lutea. In contrast, ovarian mitochondrial preparations contained relatively more Type I than did cytosol, with the mitochondrial Type I to Type II ratio increasing from approximately 0.50 in small and medium follicles to 0.88 in large follicles and 2.96 in corpora lutea. Also, mitochondrial [4-14C]cholesterol conversion and 3 beta-hydroxysteroid dehydrogenase/isomerase activities increased with follicle size and luteinization. These results suggest that Type I may play a role in the regulation of ovarian mitochondrial steroidogenesis.
mesh_terms: D000345:Affinity Labels / Q000494:pharmacology; D000818:Animals; D001386:Azides; D003338:Corpus Luteum / Q000201:enzymology* / Q000502:physiology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D005260:Female; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology*; D006080:Ovarian Follicle / Q000201:enzymology* / Q000502:physiology; D011494:Protein Kinases / Q000378:metabolism*; D013552:Swine
chemical_list: D000345:Affinity Labels; D001386:Azides; C017042:8-azidoadenosine-3',5'-monophosphate; D000242:Cyclic AMP; D011494:Protein Kinases