1. Osmotic regulation of ATA2 mRNA expression and amino acid transport System A activity.
- Author
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Alfieri RR, Petronini PG, Bonelli MA, Caccamo AE, Cavazzoni A, Borghetti AF, and Wheeler KP
- Subjects
- Animals, Biological Transport physiology, Carrier Proteins genetics, Cells, Cultured, Cycloheximide pharmacology, Dactinomycin pharmacology, Endothelium, Vascular cytology, Endothelium, Vascular drug effects, Hypertonic Solutions pharmacology, Membrane Proteins genetics, Nucleic Acid Synthesis Inhibitors pharmacology, Protein Synthesis Inhibitors pharmacology, Swine, Transfection, Water-Electrolyte Balance drug effects, beta-Alanine pharmacokinetics, Amino Acid Transport System A, Amino Acids metabolism, Carrier Proteins metabolism, Endothelium, Vascular metabolism, Membrane Proteins metabolism, RNA, Messenger metabolism, Water-Electrolyte Balance physiology, beta-Alanine analogs & derivatives
- Abstract
When porcine endothelial cells were exposed to hypertonicity, both the level of ATA2 (amino acid transporter 2) mRNA and activity of amino acid transport System A increased transiently, peaking after about 6 and 9 h, respectively. Cycloheximide, like actinomycin D, prevented both responses, showing that an earlier step also involves protein synthesis. Withdrawal of hypertonicity after 6 h increased the rate of down regulation. These findings confirm that ATA2 is a major isoform of System A and show that changes in the expression of ATA2 mRNA precede both the induction and subsequent down regulation of transport activity., (Copyright 2001 Academic Press.)
- Published
- 2001
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