Multiple protein kinases are required for basal Kv1.5 K+ channel gene expression in GH3 clonal pituitary cells.
The role of protein kinases in maintaining basal expression of voltage-gated K+ channel mRNA was examined in GH3 clonal pituitary cells. Nonspecific inhibition of protein kinases with H7 or staurosporine markedly decreases Kv1.5 K+ channel gene transcription and mRNA without producing a substantial change in Kv1.4 mRNA. Selective inhibitors for protein kinase C, Ca(2+)-calmodulin kinases, and tyrosine kinases do not affect Kv1.5 mRNA expression. In contrast, the Rp-diastereomer of adenosine 3',5'-cyclic monophosphorothioate, a specific inhibitor of protein kinase A, partially inhibits Kv1.5 mRNA expression (approximately 40%), and this effect was antagonized by 8-bromo-adenosine 3',5'-cyclic monophosphate. Thus, protein kinase A and at least one other kinase are required for basal Kv1.5 mRNA expression in pituitary cells.
Department of Pharmacology, School of Medicine, University of Pittsburgh, PA 15261.
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Takimoto
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Gealy
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Levitan
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D002999:Clone Cells; D015870:Gene Expression; D007546:Isoquinolines / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D010902:Pituitary Gland / Q000378:metabolism*; D015221:Potassium Channels / Q000235:genetics*; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D019311:Staurosporine; D014158:Transcription, Genetic / Q000187:drug effects
D000470:Alkaloids; D007546:Isoquinolines; D010879:Piperazines; D015221:Potassium Channels; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D019311:Staurosporine