title: LLC-PK1 cell mutants in cAMP metabolism respond normally to phorbol esters.
abstract: Mutants of the pig kidney cell line, LLC-PK1, affected in cAMP metabolism, were examined for cAMP-dependent protein kinase (cAMP-PK) activity and for cAMP-mediated induction of urokinase-type plasminogen activator (uPA). The FIB4 and FIB6 mutant cell lines possessed about 10% parental levels of cAMP-PK activity and concomitantly reduced uPA production (10-20% parental) in response to calcitonin, forskolin and 8-bromo cAMP. The FIB1, FIB2 and FIB5 mutant cell lines had about 70% parental levels of cAMP-PK and the synthesis of uPA was 40-60% parental. Thus, cAMP-mediated induction of uPA showed a dependence on the absolute levels of cAMP-PK. However, uPA synthesis in response to phorbol-12-myristate-13-acetate by all of the mutants was similar to parental, which indicates that enzyme induction mediated by phorbol esters does not involve cAMP or cAMP-PK.
mesh_terms: D000818:Animals; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D009154:Mutation; D010703:Phorbol Esters / Q000494:pharmacology*; D010960:Plasminogen Activators / Q000096:biosynthesis; D011494:Protein Kinases / Q000378:metabolism*; D013552:Swine; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis
chemical_list: D010703:Phorbol Esters; D000242:Cyclic AMP; D011494:Protein Kinases; D010960:Plasminogen Activators; D014568:Urokinase-Type Plasminogen Activator