Steroid-responsive sequences in the human glucocorticoid receptor gene 1A promoter

Mol Endocrinol. 2004 Apr;18(4):912-24. doi: 10.1210/me.2003-0157. Epub 2004 Jan 29.

Abstract

At least three promoters (1A, 1B, and 1C) control the expression of mRNA transcripts for the human glucocorticoid receptor (hGR) protein. An hGR 1A promoter/exon sequence (-218/+269) contains at least 12 deoxyribonuclease (DNase) I footprints that contain bound protein. Whereas four of these footprints (FP6, FP7, FP8, and FP11) contain bound hGR in protein-DNA complexes that are formed, only two (FP7 and FP11) appear to be important for the up-regulation of hGR 1A promoter/exon activity in T-lymphoblasts. Furthermore, the activity of these DNA elements depends upon the promoter context, leading to a redundant and complex regulation of expression of the hGR 1A promoter/exon. FP7 appears to be required for hormonal responsiveness in the absence of upstream sequences (+41/+191), whereas the hormonal responsiveness of FP11 requires a functional, adjacent FP12 DNA sequence. FP12 contains overlapping binding sites for the protooncogene transcription factors c-Myb and c-Ets. It seems likely that binding of either c-Myb or c-Ets to FP12 is necessary for the direct or indirect binding of the hGR to FP11 (a nonconsensus glucocorticoid response element), and the resultant steroid-responsiveness of the hGR 1A promoter/exon sequence. We propose that the identity of the accessory transcription factor bound to FP12 (c-Myb or c-Ets) may determine the nature of regulation (positive or negative) of hGR gene expression by hormone, and that this may be important for hormone-induced apoptosis in T cell acute lymphoblastic leukemia.

Publication types

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

MeSH terms

  • Binding Sites
  • DNA / metabolism
  • DNA Footprinting
  • Deoxyribonuclease I / metabolism
  • Dexamethasone / metabolism*
  • Exons / physiology
  • Humans
  • Promoter Regions, Genetic*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-ets
  • Proto-Oncogene Proteins c-myb / metabolism
  • Receptors, Glucocorticoid / biosynthesis
  • Receptors, Glucocorticoid / genetics*
  • Sequence Analysis, DNA
  • Transcription Factors / metabolism

Substances

  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • Proto-Oncogene Proteins c-myb
  • Receptors, Glucocorticoid
  • Transcription Factors
  • Dexamethasone
  • DNA
  • Deoxyribonuclease I