Distinct promoters determine alternative transcription of gpx-4 into phospholipid-hydroperoxide glutathione peroxidase variants.
A nuclear variant of phospholipid-hydroperoxide glutathione peroxidase (PHGPx, GPx-4) was considered to be derived from alternative pre-mRNA splicing in testis and to regulate sperm maturation. The genomic sequence of rat gpx-4 was established and investigated in respect to expression into the cytosolic, mitochondrial, and nuclear forms of PHGPx. In silico analysis suggested the presence of two distinct promoter regions, the upstream one leading to transcripts translating into cPHGPx or mPHGPx and the downstream one yielding nPHGPx. The promoter activity of both regions was verified by luciferase-based reporter constructs in A7r5 and H9c2 cells. The data reveal that the formation of nPHGPx is due to alternative transcription and not to alternative splicing. Transcripts encoding nPHGPx were most abundant in testis although not restricted to this organ. This observation points to a general role of the nuclear PHGPx variant in regulating cell division.
Maiorino
Matilde
M
Department of Biological Chemistry, Viale G. Colombo 3, University of Padova, I-35121 Padova, Italy. matilde.maiorino@unipd.it
Scapin
Margherita
M
Ursini
Fulvio
F
Biasolo
Mariangela
M
Bosello
Valentina
V
Flohé
Leopold
L
D020121:5' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D005091:Exons; D005786:Gene Expression Regulation; D015723:Gene Library; D017930:Genes, Reporter; D005979:Glutathione Peroxidase / Q000737:chemistry* / Q000235:genetics*; D008156:Luciferases / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D010743:Phospholipids / Q000737:chemistry*; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D014158:Transcription, Genetic
D020121:5' Untranslated Regions; D018076:DNA, Complementary; D010743:Phospholipids; D012333:RNA, Messenger; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase; D008156:Luciferases