The nuclear receptor-coactivator interaction surface as a target for peptide antagonists of the peroxisome proliferator-activated receptors.

Published

Journal Article

The peroxisome proliferator-activated receptors (PPARalpha, PPARdelta, and PPARgamma) constitute a family of nuclear receptors that regulates metabolic processes involved in lipid and glucose homeostasis. Although generally considered to function as ligand-regulated receptors, all three PPARs exhibit a high level of constitutive activity that may result from their stimulation by intracellularly produced endogenous ligands. Consequently, complete inhibition of PPAR signaling requires the development of inverse agonists. However, the currently available small molecule antagonists for the PPARs function only as partial agonists, or their efficacy is not sufficient to inhibit the constitutive activity of these receptors. Due to the lack of efficacious antagonists that interact with the ligand-binding domain of the PPARs, we decided to target an interaction that is central to nuclear receptor-mediated gene transcription: the nuclear receptor-coactivator interaction. We utilized phage display technology to identify short LXXLL-containing peptides that bind to the PPARs. Analysis of these peptides revealed a consensus binding motif consisting of HPLLXXLL. Cross-screening of these peptides for binding to other nuclear receptors enabled the identification of a high-affinity PPAR-selective peptide that has the ability to repress PPARgamma1-dependent transcription of transfected reporter genes. Most importantly, when introduced into HepG2 cells, the peptide inhibited the expression of endogenous PPARgamma1 target genes, adipose differentiation-related protein and mitochondrial 3-hydroxy-3-methylglutaryl coenzyme A synthase 2. This work lends support for the rational development of peptidomimetics that block receptor-mediated transcription by targeting the nuclear receptor-coactivator interaction surface.

Full Text

Duke Authors

Cited Authors

  • Mettu, NB; Stanley, TB; Dwyer, MA; Jansen, MS; Allen, JE; Hall, JM; McDonnell, DP

Published Date

  • October 2007

Published In

Volume / Issue

  • 21 / 10

Start / End Page

  • 2361 - 2377

PubMed ID

  • 17595321

Pubmed Central ID

  • 17595321

International Standard Serial Number (ISSN)

  • 0888-8809

Digital Object Identifier (DOI)

  • 10.1210/me.2007-0201

Language

  • eng

Conference Location

  • United States