Mutations in squirrel monkey glucocorticoid receptor impair nuclear translocation

J Steroid Biochem Mol Biol. 2005 Mar;94(4):319-26. doi: 10.1016/j.jsbmb.2004.11.010. Epub 2005 Feb 24.

Abstract

To identify the determinants of impaired glucocorticoid receptor (GR) signaling in a model of glucocorticoid resistance, cloned GR from Guyanese squirrel monkeys (gsmGR) was tagged with enhanced green fluorescent protein, and nuclear translocation was examined in transfected COS1 cells. In keeping with evidence that gsmGR transactivational competence is impaired, we found that nuclear translocation is likewise diminished in gsmGR relative to human GR (hGR). Experiments with GR chimeras revealed that replacement of the gsmGR ligand binding domain (LBD) with that from hGR increased translocation. Truncated gsmGR constructs lacking the LDB after amino acid 552 also showed increased translocation even in the absence of cortisol. Three back-mutations of gsmGR to hGR (Thr551Ser, Ala616Ser, and Ser618Ala) in the LBD confirmed that these amino acids play a role in diminished translocation.

Publication types

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

MeSH terms

  • Animals
  • COS Cells
  • Cell Nucleus / metabolism
  • Chlorocebus aethiops
  • Cloning, Molecular
  • Green Fluorescent Proteins
  • Humans
  • Hydrocortisone / pharmacology
  • Ligands
  • Nuclear Localization Signals / metabolism
  • Protein Structure, Tertiary / genetics
  • Receptors, Glucocorticoid / chemistry
  • Receptors, Glucocorticoid / genetics*
  • Receptors, Glucocorticoid / metabolism
  • Recombinant Fusion Proteins / metabolism
  • Saimiri / genetics*
  • Transcriptional Activation
  • Translocation, Genetic*

Substances

  • Ligands
  • Nuclear Localization Signals
  • Receptors, Glucocorticoid
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • Hydrocortisone