title: Evidence for catecholamine-stimulated adenylate cyclase activity in frog and rabbit corneal epithelium and cyclic AMP-dependent protein kinase and its protein substrates in frog corneal epithelium.
abstract: Evidence was obtained for catecholamine-stimulated adenylate cyclase activity in particulate fractions of frog and rabbit corneal epithelium. Epinephrine (10(-5)M) stimulated adenylate cyclase by 22 and 53% in the frog and rabbit, respectively. The corresponding changes were statistically significant (P less than 0.01) when the data was analyzed using paired variates. Preincubation with 10(-4)M propranolol eliminated any stimulatory effect by 10(-5)M isoproterenol. Adenylate cyclase activity derived from either source was activated several fold by either 10 mM NaF or 10(-5)MGpp (NH)p. Soluble fractions of homogenized frog corneal epithelium contained cyclic AMP-dependent protein kinase activity which was half-maximally stimulated by about 6 nM cyclic AMP. Evidence was also obtained for the presence of protein substrates of cyclic AMP dependent protein kinase in frog corneal epithelium. With exogenous cyclic AMP and protein kinase, a rapid 32P labelling of proteins having approximate molecular weights of 56, 46, 23 and 21 K was obtained with sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. A less marked and slower increase in phosphoprotein formation was observed when corneal membranes were incubated with cyclic AMP in the absence of added protein kinase.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D003315:Cornea / Q000201:enzymology*; D000242:Cyclic AMP / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D004837:Epinephrine / Q000494:pharmacology; D004848:Epithelium / Q000201:enzymology; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D011817:Rabbits; D011892:Rana catesbeiana; D012969:Sodium Fluoride / Q000494:pharmacology
chemical_list: D005136:Eye Proteins; D006165:Guanylyl Imidodiphosphate; D012969:Sodium Fluoride; D011433:Propranolol; D000242:Cyclic AMP; D011494:Protein Kinases; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D004837:Epinephrine