Transcriptional activation of the stearoyl-CoA desaturase 2 gene by sterol regulatory element-binding protein/adipocyte determination and differentiation factor 1

J Biol Chem. 1998 Aug 21;273(34):22052-8. doi: 10.1074/jbc.273.34.22052.

Abstract

To identify genes that are transcriptionally activated by sterol regulatory element-binding proteins (SREBPs), we utilized mRNA differential display and mutant cells that express either high or low levels of transcriptionally active SREBP. This approach identified stearoyl-CoA desaturase 2 (SCD2) as a new SREBP-regulated gene. Cells were transiently transfected with reporter genes under the control of different fragments of the mouse SCD2 promoter. Constructs containing >199 base pairs of the SCD2 proximal promoter were activated following incubation of cells in sterol-depleted medium or as a result of co-expression of SREBP-1a, SREBP-2, or rat adipocyte determination and differentiation factor 1 (ADD1). Electromobility shift assays and DNase I footprint analysis demonstrated that recombinant SREBP-1a bound to a novel cis element (5'-AGCAGATTGTG-3') in the proximal promoter of the SCD2 gene. The finding that the endogenous SCD2 mRNA levels were induced when wild-type Chinese hamster ovary fibroblasts were incubated in sterol-deficient medium is consistent with a role for SREBP in regulating transcription of the gene. These studies identify SCD2 as a new member of the family of genes that are transcriptionally regulated in response to changing levels of nuclear SREBP/ADD1. In addition, the sterol regulatory element in the SCD2 promoter is distinct from all previously characterized motifs that confer SREBP- and ADD1-dependent transcriptional activation.

Publication types

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

MeSH terms

  • Animals
  • CCAAT-Enhancer-Binding Proteins*
  • Cricetinae
  • DNA Footprinting
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Enzymologic*
  • Helix-Loop-Helix Motifs*
  • Isoenzymes / genetics*
  • Mice
  • Nuclear Proteins / metabolism*
  • RNA, Messenger / metabolism
  • Rats
  • Stearoyl-CoA Desaturase / genetics*
  • Sterol Regulatory Element Binding Protein 1
  • Sterol Regulatory Element Binding Protein 2
  • Transcription Factors / metabolism*
  • Transcriptional Activation*

Substances

  • CCAAT-Enhancer-Binding Proteins
  • DNA-Binding Proteins
  • Isoenzymes
  • Nuclear Proteins
  • RNA, Messenger
  • Srebf1 protein, mouse
  • Srebf1 protein, rat
  • Srebf2 protein, mouse
  • Sterol Regulatory Element Binding Protein 1
  • Sterol Regulatory Element Binding Protein 2
  • Transcription Factors
  • Stearoyl-CoA Desaturase