Multiple promoters exist in the human GR gene, one of which is activated by glucocorticoids

Mol Endocrinol. 2001 Aug;15(8):1381-95. doi: 10.1210/mend.15.8.0696.

Abstract

A new human GR gene sequence (hGR 1Ap/e), which is distinct from the previously identified human GR promoter and coding sequences, has been isolated and characterized. The hGR 1Ap/e sequence is approximately 31 kbp upstream of the human GR coding sequence. This sequence (2,056 bp) contains a novel promoter (the hGR 1A promoter; 1,075 bp) and untranslated exon sequence (hGR exon 1A sequence; 981 bp). Alternative splicing produces three different hGR 1A-containing transcripts, 1A1, 1A2, and 1A3. GR transcripts containing exon 1A1, 1A2, 1B, and 1C are expressed at various levels in many cancer cell lines, while the exon 1A3-containing GR transcript is expressed most abundantly in blood cell cancer cell lines. Glucocorticoid hormone treatment causes an up-regulation of exon 1A3-containing GR transcripts in CEM-C7 T-lymphoblast cells and a down-regulation of exon 1A3-containing transcripts in IM-9 B-lymphoma cells. Deoxyribonuclease I footprinting using CEM-C7 cell nuclear extract reveals four footprints in the promoter region and two intraexonic footprints. Much of the basal promoter-activating function is found in the +41/+269 sequence, which contains two deoxyribonuclease I footprints (FP5 and FP6). When this sequence is cloned into the pXP-1 luciferase reporter gene, hormone treatment causes a significant increase in luciferase activity in Jurkat T cells that are cotransfected with a GR expression vector. FP5 is an interferon regulatory factor-binding element, and it contributes significantly to basal transcription rate, but it is not activated by steroid. FP6 resembles a glucocorticoid response element and can bind GRbeta. This novel hGR 1Ap/e sequence may have future applications for the diagnosis, prognosis, and treatment of T-cell leukemia and lymphoma.

Publication types

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

MeSH terms

  • Alternative Splicing
  • Base Sequence
  • DNA Footprinting
  • DNA-Binding Proteins / genetics
  • Deoxyribonuclease I
  • Exons
  • Gene Expression
  • Glucocorticoids / pharmacology*
  • Hematologic Neoplasms / chemistry
  • Humans
  • Interferon Regulatory Factor-1
  • Jurkat Cells
  • Lymphoma, B-Cell / chemistry
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Neoplasms / chemistry
  • Phosphoproteins / genetics
  • Polymerase Chain Reaction
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / metabolism
  • Promoter Regions, Genetic*
  • RNA, Messenger / analysis
  • RNA, Messenger / genetics
  • Receptors, Glucocorticoid / drug effects
  • Receptors, Glucocorticoid / genetics*
  • Response Elements
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection
  • Tumor Cells, Cultured
  • Untranslated Regions

Substances

  • DNA-Binding Proteins
  • Glucocorticoids
  • IRF1 protein, human
  • Interferon Regulatory Factor-1
  • Phosphoproteins
  • RNA, Messenger
  • Receptors, Glucocorticoid
  • Untranslated Regions
  • Deoxyribonuclease I