Transcription factor cycling on the insulin promoter

• Published in: FEBS letters Vol. 580; no. 2; pp. 711 - 715
• Main Authors: Barrow, John, Hay, Colin W., Ferguson, Laura A., Docherty, Hilary M., Docherty, Kevin
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 23-01-2006
• Subjects: Animals; Base Sequence; Cell Line; Diabetes mellitus; E47/β2 insulin gene; Glucose - metabolism; Homeodomain Proteins - metabolism; Humans; Insulin - genetics; Insulin - metabolism; Insulin-Secreting Cells - cytology; Insulin-Secreting Cells - metabolism; Maf Transcription Factors, Large - metabolism; MafA; Mice; Molecular Sequence Data; PDX-1; Promoter Regions, Genetic; Protein Binding; Sequence Alignment; TCF Transcription Factors - metabolism; Trans-Activators - metabolism; Transcription Factor 7-Like 1 Protein; MafA; E47/β2 insulin gene; Diabetes mellitus; PDX-1
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2005.12.061

Using MIN6 β-cells and chromatin immunoprecipitation (ChIP) assays, the chronological sequence of binding of MafA, E47/β2 and PDX-1 to the insulin promoter in living β-cells were investigated. All four factors were shown to bind to the mouse insulin 2 promoter in a cyclical manner with a periodicity of approximately 10–15
min. The cyclical binding of MafA, E47 and β2 was largely unaffected by the glucose or insulin concentration in the media. However, the binding and cycling of PDX-1 was markedly abolished in low glucose (1
mM), and this was reversed in the presence of low concentrations of insulin.