Cloning and sequencing of the mouse cDNA encoding a phospholipid hydroperoxide glutathione peroxidase.
Phospholipid hydroperoxide glutathione peroxidase (PHGPx), a selenoprotein, reduces the hydroperoxides of phospholipid, cholesterol, and cholesteryl ester in biomembranes. In this study, a full-length cDNA clone encoding the PHGPx was isolated from mouse testes using a RACE (rapid amplification of cDNA ends) technique. According to sequence analysis, the cDNA encodes a polypeptide of 197 amino acids (aa) that initiates the translation at ATG(145-147) and contains an inframe TGA selenocysteine codon. It also has selenocysteine insertion sequences in the 3'-UTR that are involved in the insertion of selenocysteine at an opal codon. Moreover, the mouse PHGPx contains the active-site residues Gln108 and Trp163 that interact with selenocysteine, and the N-terminal 27-aa residues that may act as a potential mitochondrial targeting signal. According to the deduced aa analysis, mouse PHGPx shares a high level of aa identity with pig (93.4%), human (92.9%), and rat (98%) PHGPxs. However, the PHGPx mRNA particularly showed a high degree of expression in testis. This suggests that the PHGPx in testis may have more than just an antioxidant function.
Nam
S
S
Department of Veterinary Anatomy, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Japan. aa47126@hongo.ecc.u-tokyo.ac.jp
Nakamuta
N
N
Kurohmaru
M
M
Hayashi
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000235:genetics; D005979:Glutathione Peroxidase / Q000235:genetics*; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013552:Swine; D013737:Testis / Q000201:enzymology
D018076:DNA, Complementary; D012333:RNA, Messenger; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase