Molecular cloning and functional expression of nucleolar phospholipid hydroperoxide glutathione peroxidase in mammalian cells.
We cloned a full-length cDNA for phospholipid hydroperoxide glutathione peroxidase (PHGPx) including exon Ib from rat and mouse testis. The nuclear signal sequence of the N terminal of rat nuclear PHGPx possessed a different sequence from that previously reported for rat sperm nuclei GPx (SnGPx). Expression of this PHGPx-YFP (yellow fluorescent protein) fusion protein including a novel nuclear signal sequence was exclusively localized in nucleolus; although YFPs fused with only a novel nuclear signal sequence were distributed in the whole nucleus, indicating that preferential translocation of nucleolar PHGPx into nucleoli was required for the nuclear signal sequence and internal sequence of PHGPx. Low level expression of nucleolar PHGPx was detected in several tissues, but the expression of nucleolar PHGPx was extensively high in testis. Immunohistochemical analysis with anti-nucleolar PHGPx indicated that expression of nucleolar PHGPx was observed in the nucleoli in the spermatogonia, spermatocyte, and spermatid. Overexpression of 34kDa nucleolar PHGPx in RBL2H3 cells significantly suppressed cell death induced by actinomycin D and doxorubicin that induced damage in the nucleolus. These results indicated that nucleolar PHGPx plays an important role in prevention of nucleolus from damage in mammalian cells.
School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
Toshiyuki
T
Nakamura
Hirotaka
H
Imai
Naomi
N
Tsunashima
Yasuhito
Y
Nakagawa
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D002466:Cell Nucleolus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D003001:Cloning, Molecular / Q000379:methods; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D015202:Protein Engineering / Q000379:methods*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013045:Species Specificity; D013737:Testis / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D014018:Tissue Distribution
D011993:Recombinant Fusion Proteins; D003609:Dactinomycin; D004317:Doxorubicin; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase