Differential regulation of human and mouse orphan nuclear receptor small heterodimer partner promoter by sterol regulatory element binding protein-1

J Biol Chem. 2004 Jul 2;279(27):28122-31. doi: 10.1074/jbc.M313302200. Epub 2004 Apr 30.

Abstract

Small heterodimer partner (SHP; NR0B2) is an unusual orphan nuclear receptor that lacks a conventional DNA-binding domain and acts as a modulator of transcriptional activities of a number of nuclear receptors. Herein, we report that the human SHP promoter (hSHP) is activated by sterol regulatory element-binding protein-1 (SREBP-1), which regulates the expression of various genes involved in cholesterol and fatty acid synthesis. Overexpression of SREBP-1 activated the human but not mouse SHP promoter, although SREBP-2 had little effect on the SHP promoter in CV-1 cells. Serial deletion reporter assays revealed that SREBP-1-responsive region is located within the sequences from -243 to -120 bp in the hSHP promoter. DNase I footprinting, gel shift assays, and chromatin immunoprecipitation assays demonstrated that SREBP-1 binds directly to the hSHP promoter. Site-directed mutagenesis made it clear that the hSHP promoter activation by SREBP-1 is mostly mediated by the SRE1 (-186 to -195 bp) in the hSHP promoter, which is not conserved in the mouse SHP promoter. Moreover, adenovirus-mediated overexpression of SREBP-1c/ADD-1 induced SHP mRNA expression and repressed CYP7A1 expression in HepG2 cells. Finally, we found that a four-nucleotide deletion (-195CT-GAdel) in the hSHP promoter, which is reported to be associated with altered body weight and insulin secretion in human, coincides with the SRE1. This mutation strongly decreased both basal and SREBP-1 dependent activities of the hSHP promoter, because of the reduced binding of SREBP-1 to the mutated SRE1. Overall, our results demonstrate a differential regulation of human and mouse SHP promoters by SREBP-1. We propose a possible role of SREBP-1 in the species differential regulation of cholesterol and bile acid homeostasis via a novel mechanism of up-regulation of the hSHP gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Body Weight
  • CCAAT-Enhancer-Binding Proteins / biosynthesis*
  • CCAAT-Enhancer-Binding Proteins / genetics
  • Cell Line
  • Cholesterol / metabolism
  • Chromatin / metabolism
  • DNA / metabolism
  • DNA-Binding Proteins / biosynthesis*
  • DNA-Binding Proteins / genetics
  • Deoxyribonuclease I / metabolism
  • Fatty Acids / metabolism
  • Gene Deletion
  • Gene Expression Regulation
  • Humans
  • Insulin / metabolism
  • Insulin Secretion
  • Luciferases / metabolism
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Precipitin Tests
  • Promoter Regions, Genetic*
  • Protein Structure, Tertiary
  • RNA, Messenger / metabolism
  • Receptors, Cytoplasmic and Nuclear / biosynthesis*
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Species Specificity
  • Sterol Regulatory Element Binding Protein 1
  • Sterol Regulatory Element Binding Protein 2
  • Time Factors
  • Transcription Factors / biosynthesis
  • Transcriptional Activation
  • Transfection
  • Up-Regulation

Substances

  • CCAAT-Enhancer-Binding Proteins
  • Chromatin
  • DNA-Binding Proteins
  • Fatty Acids
  • Insulin
  • RNA, Messenger
  • Receptors, Cytoplasmic and Nuclear
  • SREBF1 protein, human
  • SREBF2 protein, human
  • Srebf1 protein, mouse
  • Srebf2 protein, mouse
  • Sterol Regulatory Element Binding Protein 1
  • Sterol Regulatory Element Binding Protein 2
  • Transcription Factors
  • nuclear receptor subfamily 0, group B, member 2
  • DNA
  • Cholesterol
  • Luciferases
  • Deoxyribonuclease I