Mutations in squirrel monkey glucocorticoid receptor impair nuclear translocation.
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.
Her
Song
S
Department of Psychiatry, Stanford University Medical Center, Stanford, CA 94305-5485, USA. hersong@stanford.edu
Patel
Paresh D
PD
Schatzberg
Alan F
AF
Lyons
David M
DM
D000818:Animals; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D049452:Green Fluorescent Proteins; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology; D008024:Ligands; D019913:Nuclear Localization Signals / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics; D011965:Receptors, Glucocorticoid / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012453:Saimiri / Q000235:genetics*; D015533:Transcriptional Activation; D014178:Translocation, Genetic
D008024:Ligands; D019913:Nuclear Localization Signals; D011965:Receptors, Glucocorticoid; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D006854:Hydrocortisone