The asymmetric binding of PGC-1α to the ERRα and ERRγ nuclear receptor homodimers involves a similar recognition mechanism

PLoS One. 2013 Jul 9;8(7):e67810. doi: 10.1371/journal.pone.0067810. Print 2013.


Background: PGC-1α is a crucial regulator of cellular metabolism and energy homeostasis that functionally acts together with the estrogen-related receptors (ERRα and ERRγ) in the regulation of mitochondrial and metabolic gene networks. Dimerization of the ERRs is a pre-requisite for interactions with PGC-1α and other coactivators, eventually leading to transactivation. It was suggested recently (Devarakonda et al) that PGC-1α binds in a strikingly different manner to ERRγ ligand-binding domains (LBDs) compared to its mode of binding to ERRα and other nuclear receptors (NRs), where it interacts directly with the two ERRγ homodimer subunits.

Methods/principal findings: Here, we show that PGC-1α receptor interacting domain (RID) binds in an almost identical manner to ERRα and ERRγ homodimers. Microscale thermophoresis demonstrated that the interactions between PGC-1α RID and ERR LBDs involve a single receptor subunit through high-affinity, ERR-specific L3 and low-affinity L2 interactions. NMR studies further defined the limits of PGC-1α RID that interacts with ERRs. Consistent with these findings, the solution structures of PGC-1α/ERRα LBDs and PGC-1α/ERRγ LBDs complexes share an identical architecture with an asymmetric binding of PGC-1α to homodimeric ERR.

Conclusions/significance: These studies provide the molecular determinants for the specificity of interactions between PGC-1α and the ERRs, whereby negative cooperativity prevails in the binding of the coactivators to these receptors. Our work indicates that allosteric regulation may be a general mechanism controlling the binding of the coactivators to homodimers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Protein Binding
  • Protein Conformation
  • Protein Folding
  • Protein Interaction Domains and Motifs
  • Protein Multimerization
  • Protein Subunits / chemistry
  • Protein Subunits / metabolism
  • Receptors, Estrogen / chemistry
  • Receptors, Estrogen / metabolism*
  • Scattering, Small Angle
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism*
  • X-Ray Diffraction


  • ERRalpha estrogen-related receptor
  • ESRRG protein, human
  • PPARGC1A protein, human
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Protein Subunits
  • Receptors, Estrogen
  • Transcription Factors