Evidence for post-transcriptional regulation of Na,K-ATPase by prostaglandin E1.
The stimulatory effect of PGE1 on the activity of the Na,K-ATPase in MDCK cells is associated with an increase in the rate of transcription of the Na,K-ATPase beta1 subunit gene and an increase in the rate of biosynthesis of the Na,K-ATPase [M.L. Taub, Y. Wang, I.S. Yang, P. Fiorella, S.M. Lee, Regulation of the Na,K-ATPase activity of Madin-Darby canine kidney cells in defined medium by prostaglandin E1 and 8-bromocyclic AMP, J. Cell. Physiol. 151 (1992) 337-346]. In order to further define the molecular mechanisms, transient transfection and biosynthesis studies were conducted with dibutyryl cAMP resistant (DBr) MDCK cells, defective in cAMP dependent protein kinase, and PGE1 independent (PGE1 Ind) MDCK cells with elevated intracellular cAMP. Transient transfection studies with the human Na,K-ATPase beta1 promoter/luciferase construct, pHbeta1-1141 Luc [J. Feng, J. Orlowski, J.B. Lingrel, Identification of a functional thyroid hormone response element in the upstream flanking region of the human Na,K-ATPase beta 1 gene, Nucleic Acids Res. 21 (1993) 2619-2626], showed that the stimulatory effect of PGE1 and 8Br-cAMP on beta1 subunit gene transcription is retained in the DBr and PGE1 independent variants. However, the stimulatory effect of PGE1 and 8Br-cAMP on Na,K-ATPase biosynthesis was lost in DBr (unlike PGE1 Ind) variants. These results can be explained by a defect in post-transcriptional regulation.
Borsick
Maryanne
M
Biochemistry Department, School of Medicine and Biomedical Sciences of the State University of New York at Buffalo, USA.
Rajkhowa
Trivikram
T
Taub
Mary
M
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000527:Alprostadil / Q000502:physiology*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000172:deficiency / Q000378:metabolism; D003563:Cyclic CMP / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000473:pathology; D008156:Luciferases / Q000378:metabolism; D011401:Promoter Regions, Genetic; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism*; D013963:Thyroid Hormones / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*; D014162:Transfection
D027682:Cation Transport Proteins; D017362:Cyclic AMP Response Element-Binding Protein; D013963:Thyroid Hormones; D015124:8-Bromo Cyclic Adenosine Monophosphate; D003563:Cyclic CMP; C053441:dibutyryl cyclic-3',5'-cytidine monophosphate; D000242:Cyclic AMP; D008156:Luciferases; D000251:Adenosine Triphosphatases; C022761:potassium transporting ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D000527:Alprostadil