Molecular basis for the constitutive activity of estrogen-related receptor alpha-1

J Biol Chem. 2001 Jul 27;276(30):28465-70. doi: 10.1074/jbc.M102638200. Epub 2001 May 16.

Abstract

Some orphan nuclear receptors, including estrogen-related receptor alpha-1 (ERRalpha-1), can activate gene transcription in a constitutive manner. Little is known about the molecular basis of the constitutive activity of these receptors. Our results from site-directed mutagenesis experiments have revealed that Phe-329 (analogous to Ala-350 in estrogen receptor alpha (ERalpha)) is responsible for the constitutive activity of ERRalpha-1. The ERRalpha-1 mutant F329A lost the transactivation activity and acted as a dominant negative mutant. The mammalian cell transfection experiments revealed that the ERRalpha-1 mutant F329A, like wild-type ERalpha, recognized toxaphene (an organochlorine pesticide) as an agonist. This compound was previously shown to be an antagonist of wild-type ERRalpha-1. On the other hand, like wild-type ERRalpha-1, the ERalpha mutant A350F was found to be constitutively active (as demonstrated by mammalian cell transfection and yeast two-hybrid assays). These results indicate that Phe-329 in ERRalpha-1 and Ala-350 in ERalpha play important roles in both ligand binding and transactivation function.

Publication types

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

MeSH terms

  • Alanine / chemistry
  • ERRalpha Estrogen-Related Receptor
  • Humans
  • Ligands
  • Models, Chemical
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Mutation
  • Phenylalanine / chemistry
  • Plasmids / metabolism
  • Protein Binding
  • Receptors, Cytoplasmic and Nuclear / genetics*
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Receptors, Estrogen / genetics*
  • Receptors, Estrogen / metabolism*
  • Toxaphene / pharmacology
  • Transcription, Genetic*
  • Transcriptional Activation
  • Transfection
  • Tumor Cells, Cultured
  • Two-Hybrid System Techniques

Substances

  • Ligands
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Estrogen
  • Phenylalanine
  • Toxaphene
  • Alanine