title: Impaired transactivation of the glucocorticoid receptor cloned from the Guyanese squirrel monkey.
abstract: Squirrel monkeys are among a diverse group of New World primates that demonstrate unusually high levels of circulating corticosteroids and glucocorticoid receptor (GR) insensitivity. Recent evidence suggests that overexpression of an immunophilin impairs dexamethasone binding to GR in the Bolivian squirrel monkey (Saimiri boliviensis). Here we describe the cloning, expression, and functional characterization of GR from the closely related Guyanese squirrel monkey (S. sciureus). The cloned Guyanese squirrel monkey GR (gsmGR) cDNA closely resembles human GR (hGR) cDNA, and yields a high affinity dexamethasone binding receptor when expressed in COS-1 cells. Transactivation analysis of hGR and gsmGR expressed in CV-1 cells and cultured squirrel monkey kidney (SMK) cells indicates that: (1) SMK cells elaborate a functional high activity GR from human GR cDNA; (2) gsmGR is an order of magnitude less efficient than hGR at transactivation in CV-1 and SMK cells; and (3) maximal transactivation by gsmGR is attenuated in both cell lines. Glucocorticoid resistance in S. sciureus is at least partly attributable to a naturally occurring mutation in the GR gene that results in impaired GR transactivation.
authors.affiliation: University of Michigan Medical Center, Mental Health Research Institute, 3064 NSL, 1103 E. Huron Street, Ann Arbor, MI 48104-1687, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: Patel
authors.forename: D M
authors.initials: DM
authors.lastname: Lyons
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Ngo
authors.forename: A F
authors.initials: AF
authors.lastname: Schatzberg
mesh_terms: D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D003907:Dexamethasone / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012453:Saimiri / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity; D015533:Transcriptional Activation
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D011994:Recombinant Proteins; D003907:Dexamethasone