Ablation of stimulation of a cAMP-responsive promoter in CHO cell lines defective in their cAMP-dependent protein kinase system.
We have studied the requirement for an intact cAMP-dependent protein kinase (PKA) system to regulate cAMP-mediated gene transcription in Chinese hamster ovary (CHO) cells. Wild-type CHO cells and mutant CHO cell lines selected for their resistance to the growth inhibitory effect of 8-Br-cAMP and defective in their PKA system were transiently transfected with reporter plasmids containing 2.5 and 3.0 kb of the 5'-flanking sequence of the rat tyrosine aminotransferase (TAT) gene promoter. This segment of DNA contains no CRE-like sequences, yet wild-type transfectants exhibited a specific increase in TAT promoter activity following growth in medium containing 8-Br-cAMP. In CHO cell lines defective in their PKA, the transfected TAT promoter failed to respond to cAMP treatment. We conclude that an intact PKA system is necessary for the cAMP-mediated increase in TAT promoter activity in CHO cells and that there is no requirement for a CRE to see this effect.
Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
R D
RD
Fleischmann
C
C
Jeng
M M
MM
Gottesman
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D016466:CHO Cells; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D006224:Cricetinae; D000242:Cyclic AMP / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D009154:Mutation / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011494:Protein Kinases / Q000235:genetics*; D014444:Tyrosine Transaminase / Q000235:genetics*
D015124:8-Bromo Cyclic Adenosine Monophosphate; D000242:Cyclic AMP; D015500:Chloramphenicol O-Acetyltransferase; D014444:Tyrosine Transaminase; D011494:Protein Kinases