REGULATION OF PROTEIN-KINASE A SUBUNITS BY CYCLIC ADENOSINE-3',5'-MONOPHOSPHATE IN A MOUSE SERTOLI-CELL LINE (MSC-1) - INDUCTION OF RII-BETA MESSENGER-RIBONUCLEIC-ACID IS INDEPENDENT OF CONTINUOUS PROTEIN-SYNTHESIS

We report the basal and cAMP-regulated expression of protein kinase A (PKA) subunits in a mouse Sertoli cell line (MSC-1). Of the PKA subuni ts expressed by these cells (RI alpha, RII alpha, RII beta, C alpha, C beta), Only RII beta was regulated by cAMP, An approximately 8-fold i nduction of RII beta mRNA and a 3-fold induction of RII beta protein w as observed during 48 h of cAMP-stimulation, This cAMP-mediated RII be ta mRNA induction, reaching maximal levels after approximately 12 h, d id not require ongoing protein synthesis, Fairly rapid decay of maxima lly induced RII beta mRNA was observed after removal of cAMP (t(1/2) a pproximate to 5 h). Further, ongoing transcription and translation wer e necessary for rapid degradation of RII beta mRNA, Thus, the MSC-1 ce lls expressed all the PKA subunits present in primary cultures of Sert oli cells and responded to cAMP with increased levels of RII beta at b oth mRNA and protein levels, Although the nature of some of these resp onses distinguished the observations in MSC-1 cells from previously de scribed responses in primary cultures, these cells may prove to be use ful in future studies addressing cAMP-mediated gene regulation.