A RIPE3b1-like factor binds to a novel site in the human insulin promoter in a redox-dependent manner.
In the human insulin gene, a regulatory sequence upstream of the transcription start site at -229 to -258 (the E2 element) binds a ubiquitous factor USF. The present study led to the identification of a second factor, D0, that binds to an adjacent upstream site, the C2 element, that has previously not been described. The results demonstrate that D0 exhibits similar properties to RIPE3b1, a factor shown to be an important determinant of insulin gene beta-cell-specific expression. Binding of D0 to the C2 element was abolished by the oxidising agent diamide, and the alkylating agent N-ethylmaleimide. The results indicate that expression of the insulin gene may be regulated by a redox-dependent pathway involving RIPE3b1 or a RIPE3b1-like factor.
Read
M L
ML
Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Foresterhill, UK.
Masson
M R
MR
Docherty
K
K
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000096:biosynthesis / Q000235:genetics*; D007515:Islets of Langerhans / Q000378:metabolism; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D016415:Sequence Alignment; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D007328:Insulin