Characterization of the 5' flanking region of the human MnSOD gene.
Human manganese-containing superoxide dismutase (MnSOD) is a nuclear encoded mitochondrial protein that scavenges potentially toxic superoxide radicals by dismuting O2- to O2 plus H2O2. To understand the molecular mechanism governing the transcriptional regulation of the human MnSOD gene, I have isolated and sequenced a genomic clone containing the 5' flanking region of the human MnSOD gene. One major transcription start site was mapped by primer extension to a guanine residue 67 base pairs upstream from the translation start site. Eight putative Sp1 binding elements and one AP1 consensus sequence, but no TATA or CAAT box, were found in the promoter region. Furthermore, a series of chimerical/CAT reporter gene constructs were used to transfect human hepatocellular carcinoma(HepG2) human neuroblastoma and human skin fibroblast cell lines to characterize the promoter and regulatory region of the human MnSOD gene. The results show that human MnSOD gene expression is governed by one promoter and that the basic promoter is located between nucleotides -34 and +38. The results also indicate that both positive and negative elements are involved in the regulation of the cell-type specific expression of the human MnSOD gene. The functional studies indicate that the Sp1 binding sites or G+C rich regions play an important role in regulation of expression of the human MnSOD gene in vivo.
Zhang
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Department of Hematology, The Jewish Hospital of St. Louis, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D017930:Genes, Reporter; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics*; D014162:Transfection
D018076:DNA, Complementary; D012333:RNA, Messenger; D013482:Superoxide Dismutase; D015500:Chloramphenicol O-Acetyltransferase