Petersen H V, Peshavaria M, Pedersen A A, Philippe J, Stein R, Madsen O D, Serup P
Hagedorn Research Laboratory, Gentofte, Denmark.
FEBS Lett. 1998 Jul 24;431(3):362-6. doi: 10.1016/s0014-5793(98)00776-5.
Glucose-stimulated expression of the insulin gene in beta cells is mediated by the PDX-1 transcription factor. In this report, we show that stimulation results from effects on activation and DNA-binding potential. Thus, glucose specifically stimulated expression in MIN6 beta cells from chimeras of PDX-1 and the GAL4 DNA-binding domain which spanned the N-terminal PDX-1 activation domain located between amino acids 1 to 79. GAL4:PDX activity was induced over physiological glucose concentrations and was also regulated by effectors of this response. The level of endogenous PDX-1 binding and phosphorylation were also induced under these conditions. We discuss how changes in PDX-1 phosphorylation may influence activity in glucose-treated beta cells.
