Selenoprotein W gene regulation by selenium in L8 cells.
The effects of selenium on selenoprotein W gene expression were examined in cultured L8 rat skeletal muscle cells. Selenoprotein W contains selenium as selenocysteine in the primary protein structure and levels of this selenoprotein are affected by selenium. Northern blots indicated that there were no significant changes (P < 0.05) in selenoprotein W mRNA levels during cell proliferation and differentiation. Reduction of selenium concentration in the medium decreased the selenoprotein W mRNA levels. Nuclear run-on experiments with isolated L8 nuclei showed the same rate of selenoprotein W mRNA synthesis in cells cultured in either low selenium or selenium supplemented medium, suggesting that the transcription rate of the selenoprotein W gene is independent of selenium. Measurement of the selenoprotein W mRNA half-life in myoblasts treated with the transcription inhibitor, alpha-amanitin, showed that selenoprotein W mRNA levels decreased over time with an estimated half-life of 57 h for cells grown in low selenium medium. Selenium treatment increased the selenoprotein W mRNA half-life 2-fold. These data suggest that selenium stabilizes selenoprotein W mRNA but has no effect on transcription.
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Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis 97331, USA.
Ream
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Whanger
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D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects; D066298:In Vitro Techniques; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D051381:Rats; D012643:Selenium / Q000378:metabolism / Q000494:pharmacology*; D051151:Selenoprotein W; D051140:Selenoproteins
D011506:Proteins; D051151:Selenoprotein W; D051140:Selenoproteins; D012643:Selenium