Activation of alpha-myosin heavy chain gene expression by cAMP in cultured fetal rat heart myocytes.
The effect of cAMP on cardiac myosin heavy chain (MHC) gene expression in primary cultures of 18-day-old fetal rat heart myocytes was investigated. When myocytes were treated with either 10 microM forskolin or 1 mM 8-bromo-cAMP for 48 h, the relative amount of the V1 to -V3 myosin isoform ratio increased 3-fold. The abundance of alpha-MHC mRNA was also increased 3-to-4-fold in forskolin treated vs control cells. However, no appreciable change was observed in the level of beta-MHC mRNA. In addition, a 70% increase in the transcription rate of the cardiac MHC gene was observed by nuclear run-on assay following treatment of cells with 10 microM forskolin for 12 h. These results demonstrate the preferential induction of alpha-MHC mRNA by cAMP which is, in part, mediated by transcriptional activation of the gene.
Gupta
M P
MP
Department of Medicine, University of Chicago, IL 60637.
Gupta
M
M
Stewart
A
A
Zak
R
R
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology*; D000242:Cyclic AMP / Q000502:physiology*; D005333:Fetus; D005786:Gene Expression Regulation / Q000187:drug effects*; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D009218:Myosins / Q000235:genetics*; D015345:Oligonucleotide Probes; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D051381:Rats; D014158:Transcription, Genetic / Q000187:drug effects
D007527:Isoenzymes; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D012313:RNA; D000242:Cyclic AMP; D009218:Myosins