Cloning and sequencing of the mouse cDNA encoding a phospholipid hydroperoxide glutathione peroxidase

• Published in: Gene Vol. 198; no. 1; pp. 245 - 249
• Main Authors: Nam, Sang-yoon, Nakamuta, Nobuaki, Kurohmaru, Masamichi, Hayashi, Yoshihiro
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.1997
• Subjects: Amino Acid Sequence; Animals; Consensus Sequence; DNA, Complementary - genetics; Glutathione Peroxidase - genetics; Humans; Male; Mice; Molecular Sequence Data; Opal codon; RACE technique; Rats; RNA, Messenger - genetics; Selenocysteine; Selenocysteine insertion sequence; Selenoprotein; Sequence Alignment; Sequence Homology, Amino Acid; Swine; Testis - enzymology; aa, amino acid(s); DIG, digoxigenin; PHGPx, phospholipid hydroperoxide GPx; ORF, open reading frame; Selenocysteine; Opal codon; UTR, untranslated region; Sec, selenocysteine; Selenoprotein; nt, nucleotide(s); RACE technique; RACE, rapid amplification of cDNA ends; GPx, glutathione peroxidase; Selenocysteine insertion sequence; RT-PCR, reverse transcription-polymerase chain reaction
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/S0378-1119(97)00321-1

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 Gln 108 and Trp 163 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.