The alpha-subunit mRNAs for Gs and Go2 are differentially regulated by protein kinase A and protein kinase C in rat Sertoli cells.
In the present study, we have examined regulatory effects of protein kinase A and protein kinase C activation by 8-CPTcAMP and TPA, respectively, on mRNAs for various G protein alpha-subunits and corresponding immunoreactive proteins in rat Sertoli cells. Gs alpha and Go alpha mRNA levels were transiently increased 1.5-fold and 4-fold, respectively, by 8-CPTcAMP in cultured Sertoli cells. This up-regulation of mRNAs for Gs alpha and Go alpha was also observed when Sertoli cells were incubated in the presence of FSH. When protein synthesis was inhibited by cycloheximide, the cAMP-mediated stimulation of Gs alpha mRNA was abolished, whereas Go alpha mRNA was superinduced to a 50- to 100-fold higher level than basal. Activation of protein kinase C with TPA had a strong, synergistic effect on cAMP-mediated stimulation of Gs alpha mRNA, whereas the cAMP-mediated stimulation of Go alpha mRNA was completely blocked. Surprisingly, changes in mRNA levels were not accompanied by any alterations in the levels of immunoreactive Gs alpha and Go alpha proteins.
Taskén
K A
KA
Institute of Medical Biochemistry, University of Oslo, Norway.
Jacobsen
F W
FW
Eikvar
L
L
Hansson
V
V
Haugen
T B
TB
D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics*; D008297:Male; D011493:Protein Kinase C / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D012708:Sertoli Cells / Q000187:drug effects / Q000201:enzymology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology
D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D013873:Thionucleotides; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D013755:Tetradecanoylphorbol Acetate