Proenkephalin gene expression: interaction of glucocorticoid and cAMP regulatory elements. Academic Article uri icon

Overview

abstract

  • We used gel shift assays to determine the affinities of a 15 base glucocorticoid response element (GRE) derived from the rat proenkephalin (Penk) gene for the glucocorticoid receptor. A DNA binding domain of the glucocorticoid receptor interacted with a rat GRE (RGRE) with an apparent affinity intermediate between that of a consensus positive GRE oligo (GRE+) and a mismatch GRE oligo (GRE-). When inserted in front of a chloramphenicol acyl transferase (CAT) construct that is driven by a Penk promoter containing a cAMP response element, dexamethasone (10 microM) produced a 5-fold increase with GRE+, a small increase with RGRE, and no change with GRE- or the Penk promoter alone. Forskolin (20 microM) stimulated CAT activity 4- to 9-fold with each construct. However, dexamethasone plus forskolin caused a synergistic induction of CAT expression with the GRE+ oligo, no effect with the RGRE and an antagonistic effect with the Penk promoter alone and the GRE- oligo. These results demonstrate that GRE+, and to a lesser degree RGRE, can mimic the response of the endogenous Penk gene to dexamethasone and forskolin. Furthermore, a dexamethasone activated glucocorticoid receptor may inhibit cAMP mediated transcription of the Penk gene when a GRE+ or RGRE is not present.

publication date

  • May 16, 1995

Research

keywords

  • Cyclic AMP
  • Dexamethasone
  • Enkephalins
  • Protein Precursors

Identity

Scopus Document Identifier

  • 0029028587

Digital Object Identifier (DOI)

  • 10.1006/bbrc.1995.1700

PubMed ID

  • 7755638

Additional Document Info

volume

  • 210

issue

  • 2