Characterization of promoter elements regulating the expression of the human neurotensin/neuromedin N gene

J Biol Chem. 2011 Jan 7;286(1):542-54. doi: 10.1074/jbc.M110.145664. Epub 2010 Oct 28.

Abstract

Expression of the gene encoding neurotensin/neuromedin N (NT/N) is mostly limited to the brain and specialized enteroendocrine N cells in the distal small intestine. We have identified key regulatory elements in the promoter region that are involved in human NT/N (hNT/N) gene expression in the novel human endocrine cell line, BON, which resembles intestinal N cells in several important aspects including NT/N precursor protein processing, ratios of different NT/N mRNA isoforms, and high levels of constitutive expression of the NT/N gene. In this study, we demonstrated multiple cis-regulatory elements including a proximal region containing a cAMP-responsive element (CRE)/AP-1-like element that binds both the AP-1 and CRE-binding protein (CREB)/ATF proteins (c-Jun, ATF-1, ATF-2, JunD, and CREB). Similar to the rat NT/N gene, this region is critical for constitutive hNT/N gene expression. Moreover, we identified a novel region that binds the orphan hormone receptor, NR2F2. We have demonstrated that the C terminus of NR2F2 strongly represses hNT/N transcription, whereas an N-terminal domain antagonizes this repressive effect. Regulation of NT/N expression by NR2F2 may have important consequences for lipid metabolism. We speculate that a complex interplay between the proximal CRE/AP-1-like motif and NR2F2 binding region exists to regulate hNT/N expression, which is critical for the high level of constitutive expression of NT/N in enteroendocrine cells. Finally, the BON cell line provides a unique model to characterize the factors regulating expression of the hNT/N gene and to better understand the mechanisms responsible for terminal differentiation of the N cell lineage in the gut.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Activating Transcription Factors / metabolism
  • Animals
  • Base Sequence
  • COS Cells
  • COUP Transcription Factor II / chemistry
  • COUP Transcription Factor II / metabolism
  • Cell Line
  • Chlorocebus aethiops
  • Cyclic AMP / genetics
  • Cyclic AMP Response Element-Binding Protein / metabolism
  • Deoxyribonuclease I / metabolism
  • Gene Expression Regulation / genetics*
  • Humans
  • Mutagenesis, Site-Directed
  • Mutation
  • Neurotensin / deficiency
  • Neurotensin / genetics*
  • Neurotensin / metabolism
  • Peptide Fragments / deficiency
  • Peptide Fragments / genetics*
  • Peptide Fragments / metabolism
  • Promoter Regions, Genetic / genetics*
  • Rats
  • Response Elements / genetics
  • Sequence Deletion
  • Transcription Factor AP-1 / metabolism

Substances

  • Activating Transcription Factors
  • COUP Transcription Factor II
  • Cyclic AMP Response Element-Binding Protein
  • NR2F2 protein, human
  • Peptide Fragments
  • Transcription Factor AP-1
  • neuromedin N
  • Neurotensin
  • Cyclic AMP
  • Deoxyribonuclease I