Definition of the molecular basis for estrogen receptor-related receptor-alpha-cofactor interactions

Mol Endocrinol. 2007 Jan;21(1):62-76. doi: 10.1210/me.2006-0179. Epub 2006 Oct 19.


Estrogen receptor-related receptor-alpha (ERRalpha) is an orphan nuclear receptor that does not appear to require a classical small molecule ligand to facilitate its interaction with coactivators and/or hormone response elements within target genes. Instead, the apo-receptor is capable of interacting in a constitutive manner with coactivators that stimulate transcription by acting as protein ligands. We have screened combinatorial phage libraries for peptides that selectively interact with ERRalpha to probe the architecture of the ERRalpha-coactivator pocket. In this manner, we have uncovered a fundamental difference in the mechanism by which this receptor interacts with peroxisome proliferator-activated receptor-gamma coactivator-1alpha, as compared with members of the steroid receptor coactivator subfamily of coactivators. Our findings suggest that it may be possible to develop ERRalpha ligands that exhibit different pharmacological activities as a consequence of their ability to differentially regulate coactivator recruitment. In addition, these findings have implications beyond ERRalpha because they suggest that subtle alterations in the structure of the activation function-2 pocket within any nuclear receptor may enable differential recruitment of coactivators, an observation of notable pharmaceutical importance.

Publication types

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

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • HeLa Cells
  • Humans
  • Ligands
  • Models, Molecular
  • Molecular Sequence Data
  • Peptide Library
  • Promoter Regions, Genetic
  • Protein Binding
  • Protein Structure, Tertiary
  • Receptors, Estrogen / chemistry*
  • Transcription Factors / chemistry
  • Transcription, Genetic
  • Two-Hybrid System Techniques


  • ERRalpha estrogen-related receptor
  • Ligands
  • Peptide Library
  • Receptors, Estrogen
  • Transcription Factors
  • peroxisome-proliferator-activated receptor-gamma coactivator-1