The human copper-zinc superoxide dismutase gene (SOD1) proximal promoter is regulated by Sp1, Egr-1, and WT1 via non-canonical binding sites.
Human copper-zinc superoxide dismutase (Cu,Zn-SOD) participates in the control of reactive oxygen intermediate intracellular concentration. In this study, we show that phorbol 12-myristate 13-acetate (PMA) increases Cu,Zn-SOD mRNA expression within 30 min. The sequence between nucleotides -71 and -29 is essential for both basal and PMA-induced gene expression. This region includes an Sp1-binding site that is also recognized by a possible Sp1-like protein and by Egr-1 in a PMA-inducible manner. Egr-1 and two splicing variants of the Egr-related protein WT1 were able to transactivate the SOD1 promoter in co-transfection experiments. Sp1 and the possible Sp1-like proteins bind to two overlapping, but distinct sequences. However, Egr-1 and Sp1 seem to interact with two sites that are either identical or very close to each other. None of these sites fit the consensus sequences previously reported for these proteins. Analysis of various mutants of the SOD1 proximal promoter revealed that the region that binds Sp1 and Egr-1 is required for both basal and Egr-1-driven expression. Interplay between different members of the Sp1 family, Egr-1, and different splicing variants of WT1 in the SOD1 proximal promoter may provide clues about the physiological function of Cu,Zn-SOD.
Minc
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E
Institut d'Oncologie Cellulaire et Moléculaire Humaine, 129, Route de Stalingrad, F-93000 Bobigny, France.
de Coppet
P
P
Masson
P
P
Thiery
L
L
Dutertre
S
S
Amor-Guéret
M
M
Jaulin
C
C
D001483:Base Sequence; D001665:Binding Sites; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D051766:Early Growth Response Protein 1; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D017874:Immediate-Early Proteins; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*; D025721:WT1 Proteins
D017931:DNA Primers; D004268:DNA-Binding Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D025721:WT1 Proteins; D013482:Superoxide Dismutase; D013755:Tetradecanoylphorbol Acetate