Transcription of the gene for the gap junctional protein connexin43 and expression of functional cell-to-cell channels are regulated by cAMP.
We investigated the mechanism by which cyclic AMP (cAMP) induces gap junctional communication via cell-to-cell channels in a communication-deficient rat Morris hepatoma cell line. We found that under basal conditions, the cells transcribe cx43 at a low level but do not transcribe cx26 or cx32. Elevation of intracellular cAMP, which induced communication, increased cx43 mRNA 15- to 40-fold and the rate of cx43 transcription 6-fold. Cx43 protein was detected by immunostaining in junctions of only those cells in which communication had been induced. We found the regulation by cAMP also in other cell lines; namely, in those with a low basal level of cx43 mRNA.
Mehta
P P
PP
Department of Physiology and Biophysics, University of Miami School of Medicine, Florida 33101.
Yamamoto
M
M
Rose
B
B
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D015152:Blotting, Northern; D002450:Cell Communication; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002461:Cell Line, Transformed; D005576:Colforsin / Q000494:pharmacology; D017630:Connexins; D000242:Cyclic AMP / Q000502:physiology*; D015342:DNA Probes; D005786:Gene Expression Regulation; D015151:Immunoblotting; D007365:Intercellular Junctions / Q000502:physiology*; D008114:Liver Neoplasms, Experimental; D008565:Membrane Proteins / Q000235:genetics*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D017630:Connexins; D015342:DNA Probes; D008565:Membrane Proteins; D012333:RNA, Messenger; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000242:Cyclic AMP