ISL1 physically interacts with BETA2 to promote insulin gene transcriptional synergy in non-beta cells

Biochim Biophys Acta. 2005 Dec 20;1731(3):154-9. doi: 10.1016/j.bbaexp.2005.08.013. Epub 2005 Nov 2.

Abstract

ISL1 is a LIM homeodomain protein that plays an important role in insulin gene transcriptional activation and islet cell formation. BETA2 is a transcription factor in the basic helix-loop-helix (bHLH) family, which activates expression of tissue-specific genes in several developmental systems. In this study, we investigated the functional and physical interactions of ISL1 and BETA2 in promoting insulin gene transcription in non-beta cells. Using the luciferase assay, we demonstrated that ISL1 and BETA2 could activate insulin gene transcription synergistically. Co-immunoprecipitation also supported that ISL1 and BETA2 appear in one complex and this physical interaction mediates the synergy between these two proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Cells, Cultured
  • Enhancer Elements, Genetic
  • Gene Expression Regulation
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Humans
  • Insulin / genetics*
  • Insulin / metabolism
  • LIM-Homeodomain Proteins
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Promoter Regions, Genetic
  • Protein Binding / genetics
  • Protein Binding / physiology*
  • Recombinant Proteins
  • Transcription Factors
  • Transcription, Genetic / physiology*
  • Transfection

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Homeodomain Proteins
  • Insulin
  • LIM-Homeodomain Proteins
  • NEUROD1 protein, human
  • Nerve Tissue Proteins
  • Recombinant Proteins
  • Transcription Factors
  • insulin gene enhancer binding protein Isl-1