Evolutionary conservation of an atypical glucocorticoid-responsive element in the human tyrosine hydroxylase gene

C. S. Sheela Rani, Alexandra Soto-Pina, Lorraine Iacovitti, Randy Strong

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

The human tyrosine hydroxylase (hTH) gene has a 42 bp evolutionarily conserved region designated (CR) II at -7.24 kb, which bears 93% homology to the region we earlier identified as containing the glucocorticoid response element, a 7 bp activator protein-1 (AP-1)-like motif in the rat TH gene. We cloned this hTH-CRII region upstream of minimal basal hTH promoter in luciferase (Luc) reporter vector, and tested glucocorticoid responsiveness in human cell lines. Dexamethasone (Dex) stimulated Luc activity of hTH-CRII in HeLa cells, while mifepristone, a glucocorticoid receptor (GR) antagonist, prevented Dex stimulation. Deletion of the 7 bp 5′-TGACTAA at -7243 bp completely abolished the Dex-stimulated Luc activity of hTH-CRII construct. The AP-1 agonist, tetradeconoyl-12,13-phorbol acetate (TPA), also stimulated hTH promoter activity, and Dex and TPA together further accentuated this response. Chromatin immunoprecipitation assays revealed the presence of both GR and AP-1 proteins, especially Jun family members, at this hTH promoter site. Dex did not stimulate hTH promoter activity in a catecholaminergic cell line, which had low endogenous GR levels, but did activate the response when GR was expressed exogenously. Thus, our studies have clearly identified a glucocorticoid-responsive element in a 7 bp AP-1-like motif in the promoter region at -7.24 kb of the human TH gene.

Original languageEnglish (US)
Pages (from-to)19-28
Number of pages10
JournalJournal of neurochemistry
Volume126
Issue number1
DOIs
StatePublished - Jul 1 2013
Externally publishedYes

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Keywords

  • AP-1
  • glucocorticoid receptor
  • glucocorticoid response element
  • tyrosine hydroxylase

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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