Insulin enhancer binding protein has helix-loop-helix structure.
Insulin gene expression is restricted to pancreatic B cells and the 5' flanking region is responsible for the tissue specificity. The GCCATCTG motif in this region of the rat insulin 1 gene functions as an enhancer for insulin transcription. A cDNA coding for a GCCATCTG motif-binding protein (IEBP1) was isolated from a rat pancreatic B cell tumor lambda gt11 library. The IEBP1 protein was found to be the rat counterpart of the immunoglobulin (Ig) enhancer binding protein E12/47 having a helix-loop-helix domain. This result indicates that the Ig gene and insulin gene employ the same (or a similar) binding protein as a part of their transcriptional apparatus.
Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Y
Y
Shibasaki
H
H
Sakura
F
F
Takaku
M
M
Kasuga
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D004274:DNA, Recombinant / Q000032:analysis*; D004268:DNA-Binding Proteins / Q000032:analysis / Q000302:isolation & purification*; D004742:Enhancer Elements, Genetic; D007328:Insulin / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D016328:NF-kappa B; D011487:Protein Conformation; D051381:Rats; D014157:Transcription Factors; D014407:Tumor Cells, Cultured
D051792:Basic Helix-Loop-Helix Proteins; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D007328:Insulin; D016328:NF-kappa B; D014157:Transcription Factors; C064943:IEBP1 protein, rat