Active transcription of the selenium-dependent glutathione peroxidase gene in selenium-deficient rats.
Selenium-dependent glutathione peroxidase (Se-GSH-Px, Ec.1.11.1.9) is the best characterized selenoenzyme in higher animals. However, neither the mechanism whereby selenium (Se) becomes incorporated into the enzyme nor the level at which the expression of Se-GSH-Px gene is regulated by Se is fully understood. In the current investigation, we have determined the relative rates of the transcription of the Se-GSH-Px gene in purified liver nuclei isolated from rats fed on Se-supplemented or Se-deficient diets. No significant difference in the transcription rates appeared in these two groups. These results are consistent with the previous observations that active message for Se-GSH-Px- that is, translatable mRNA for Se-GSH-Px- is present in Se-deficient tissues (Li et al., J. Biol. Chem., 265, 108-113, 1990). The data also suggest that the alteration of Se-GSH-Px activity and the corresponding protein and mRNA levels in rats subjected to dietary Se manipulation can be attributed only to post-transcriptional regulation.
Chang
M
M
Environmental Resources Research Institute, Pennsylvania State University, University Park 16802.
Reddy
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CC
D000818:Animals; D002467:Cell Nucleus / Q000502:physiology; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005979:Glutathione Peroxidase / Q000235:genetics*; D008099:Liver / Q000201:enzymology; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D012643:Selenium / Q000172:deficiency / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects
D012333:RNA, Messenger; D004247:DNA; D005979:Glutathione Peroxidase; D012643:Selenium