A tissue-specific nuclear factor binds to multiple sites in the human insulin-gene enhancer.
Sequence-specific binding of proteins from an insulin-secreting cell line (RINm-5F) to the human insulin-gene 5' region were examined by gel-retardation and methylation-interference analysis. Specific binding of a nuclear factor to sites between nucleotides -210 to -217 and -77 to -84 was detected. The same binding activity was shown at an upstream site (-313 to -320) with low affinity. Studies using mutated binding-site probes delineated a sequence 5'-C(T/C)CTAATG-3' for high-affinity interactions. This binding activity was also present in another insulin-producing cell line (HIT.T15), but not in extracts from cell lines that did not express the insulin gene (HeLa, HL60). Cross-species comparisons show that this sequence element is highly conserved and may thus play an important role in the cell-specific regulation of insulin-gene transcription.
Boam
D S
DS
Department of Medicine, University of Birmingham, Queen Elizabeth Hospital, Edgbaston, U.K.
Docherty
K
K
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000502:physiology*; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D006801:Humans; D007328:Insulin / Q000235:genetics*; D008745:Methylation; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000502:physiology*; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; D007328:Insulin; D009687:Nuclear Proteins; D014157:Transcription Factors