Expression of glutathione peroxidase I gene in selenium-deficient rats.
We have characterized a cDNA pGPX1211 encoding rat glutathione peroxidase I. The selenocysteine in the protein corresponded to a TGA codon in the coding region of the cDNA, similar to earlier findings in mouse and human genes, and a gene encoding the formate dehydrogenase from E. coli, another selenoenzyme. The rat GSH peroxidase I has a calculated subunit molecular weight of 22,155 daltons and shares 95% and 86% sequence homology with the mouse and human subunits, respectively. The 3'-noncoding sequence (greater than 930 bp) in pGPX1211 is much longer than that of the human sequences. We found that glutathione peroxidase I mRNA, but not the polypeptide, was expressed under nutritional stress of selenium deficiency where no glutathione peroxidase I activity can be detected. The failure of detecting any apoprotein for the glutathione peroxidase I under selenium deficiency and results published from other laboratories supports the proposal that selenium may be incorporated into the glutathione peroxidase I co-translationally.
Reddy
A P
AP
Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.
Hsu
B L
BL
Reddy
P S
PS
Li
N Q
NQ
Thyagaraju
K
K
Reddy
C C
CC
Tam
M F
MF
Tu
C P
CP
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D005979:Glutathione Peroxidase / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009710:Nucleotide Mapping; D051381:Rats; D012643:Selenium / Q000172:deficiency*
D004247:DNA; D005979:Glutathione Peroxidase; D004262:DNA Restriction Enzymes; D012643:Selenium