Expression, signaling and function of Egr transcription factors in pancreatic β-cells and insulin-responsive tissues

Mol Cell Endocrinol. 2014 May 5;388(1-2):10-9. doi: 10.1016/j.mce.2014.03.001. Epub 2014 Mar 12.

Abstract

Egr-1 and the related zinc finger transcription factors Egr-2, Egr-3, and Egr-4 are stimulated by many extracellular signaling molecules and represent a convergence point for intracellular signaling cascades. Egr-1 expression is induced in insulinoma cells and pancreatic β-cells following stimulation with either glucose, or pregnenolone sulfate. Moreover, stimulation of Gαq and Gαs-coupled receptors enhances EGR-1 gene transcription. Functional studies revealed that Egr transcription factors control insulin biosynthesis via regulation of Pdx-1 expression. Glucose homeostasis and pancreatic islet size are regulated by Egr transcription factors, indicating that these proteins control central physiological parameters regulated by pancreatic β-cells. In addition, Egr-1 is an integral part of the insulin receptor signaling cascade in insulin-responsive tissues and influences insulin resistance.

Keywords: Beta cell; Egr-1; Insulin; Pancreas; Pdx-1; Transcription.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Early Growth Response Transcription Factors / genetics
  • Early Growth Response Transcription Factors / metabolism*
  • Gene Expression
  • Gene Expression Regulation
  • Humans
  • Insulin
  • Insulin-Secreting Cells / metabolism*
  • Insulinoma / metabolism
  • Organ Specificity
  • Promoter Regions, Genetic
  • Signal Transduction

Substances

  • Early Growth Response Transcription Factors
  • Insulin