Egr-1—A Ca2+-regulated transcription factor

The biosynthesis of the zinc finger transcription factor Egr-1 is stimulated by many extracellular signaling molecules including hormones, neurotransmitters, growth and differentiation factors. The Egr-1 gene represents a convergence point for many intracellular signaling cascades. An increase of the intracellular Ca2+ concentration, by activating ionotropic or Gαq/11-coupled receptors or voltage-gated L-type Ca2+ channels, is often the prerequisite for enhanced Egr-1 gene transcription. This increase has been observed following stimulation with extracellular signaling molecules including ATP, glutamate, thrombin, carbachol, gonadotropin-releasing hormone, or glucose. Egr-1 is thus a Ca2+ regulated transcription factor – similar to CREB, NFAT, NF-κB and others. This review also discusses the importance of the cytoplasmic and nuclear Ca2+ concentration in transcriptional regulation of the Egr-1 gene.