Adaptive regulation of MDCK cell taurine transporter (pNCT) mRNA: transcription of pNCT gene is regulated by external taurine concentration.
NaCl-dependent taurine transporter (pNCT) activity of MDCK cells (Madin-Darby canine kidney) is up- or down-regulated by medium taurine manipulation. In this study we found that the abundance of pNCT mRNA was up- or down-regulated after cells were incubated in media containing 0 microM taurine or 500 microM taurine for 24 h. Down-regulation was observed after 12 h exposure to high taurine (500 microM) and mRNA abundance was appreciably reduced after 72 h exposure. Nuclear run-off assays show that the gene for pNCT is induced at the transcriptional level by taurine. Addition of cycloheximide blocked the adaptive response and reduced transcription of pNCT mRNA in MDCK cells. Cycloheximide had virtually no effect on pNCT mRNA stability, suggesting that ongoing protein synthesis is required for adaptive regulation of pNCT gene transcription.
Han
X
X
Department of Pediatrics, University of Tennessee and the Crippled Children's Foundation Research Center at Le Bonheur Children's Medical Center, Memphis 38103, USA.
Budreau
A M
AM
Chesney
R W
RW
D000818:Animals; D002352:Carrier Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D002478:Cells, Cultured; D003470:Culture Media; D003513:Cycloheximide / Q000494:pharmacology; D004285:Dogs; D005786:Gene Expression Regulation; D007668:Kidney / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D026901:Membrane Transport Proteins; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011506:Proteins / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D013654:Taurine / Q000378:metabolism* / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic; D000099247:Taurine Transporters
D002352:Carrier Proteins; D003470:Culture Media; D003513:Cycloheximide; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D011493:Protein Kinase C; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D012333:RNA, Messenger; D013654:Taurine; D013755:Tetradecanoylphorbol Acetate; D000099247:Taurine Transporters