Glucose stimulates the activation domain potential of the PDX-1 homeodomain transcription factor

FEBS Lett. 1998 Jul 24;431(3):362-6. doi: 10.1016/s0014-5793(98)00776-5.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Cell Line
  • DNA Probes
  • DNA-Binding Proteins
  • Fungal Proteins / metabolism
  • Gene Expression Regulation
  • Glucose / pharmacology*
  • Homeodomain Proteins / metabolism*
  • Humans
  • Insulin / genetics
  • Islets of Langerhans / cytology
  • Islets of Langerhans / drug effects
  • Islets of Langerhans / metabolism
  • Phosphorylation
  • Saccharomyces cerevisiae Proteins*
  • Trans-Activators / metabolism*
  • Transcription Factors*
  • Transcriptional Activation

Substances

  • DNA Probes
  • DNA-Binding Proteins
  • Fungal Proteins
  • GAL4 protein, S cerevisiae
  • Homeodomain Proteins
  • Insulin
  • Saccharomyces cerevisiae Proteins
  • Trans-Activators
  • Transcription Factors
  • pancreatic and duodenal homeobox 1 protein
  • Glucose