title: Live cell imaging unveils multiple domain requirements for in vivo dimerization of the glucocorticoid receptor.
abstract: Glucocorticoids are essential for life, but are also implicated in disease pathogenesis and may produce unwanted effects when given in high doses. Glucocorticoid receptor (GR) transcriptional activity and clinical outcome have been linked to its oligomerization state. Although a point mutation within the GR DNA-binding domain (GRdim mutant) has been reported as crucial for receptor dimerization and DNA binding, this assumption has recently been challenged. Here we have analyzed the GR oligomerization state in vivo using the number and brightness assay. Our results suggest a complete, reversible, and DNA-independent ligand-induced model for GR dimerization. We demonstrate that the GRdim forms dimers in vivo whereas adding another mutation in the ligand-binding domain (I634A) severely compromises homodimer formation. Contrary to dogma, no correlation between the GR monomeric/dimeric state and transcriptional activity was observed. Finally, the state of dimerization affected DNA binding only to a subset of GR binding sites. These results have major implications on future searches for therapeutic glucocorticoids with reduced side effects.
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland, United States of America; Department of Biological Chemistry, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina; IFIBYNE-CONICET, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Diego M
authors.initials: DM
authors.lastname: Presman
authors.affiliation: Department of Biological Chemistry, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina; IFIBYNE-CONICET, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: M Florencia
authors.initials: MF
authors.lastname: Ogara
authors.affiliation: Department of Biological Chemistry, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Martín
authors.initials: M
authors.lastname: Stortz
authors.affiliation: Department of Organic Chemistry/UMYMFOR-CONICET, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Lautaro D
authors.initials: LD
authors.lastname: Alvarez
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland, United States of America; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom.
authors.forename: John R
authors.initials: JR
authors.lastname: Pooley
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland, United States of America.
authors.forename: R Louis
authors.initials: RL
authors.lastname: Schiltz
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland, United States of America.
authors.forename: Lars
authors.initials: L
authors.lastname: Grøntved
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland, United States of America.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Johnson
authors.affiliation: Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Mittelstadt
authors.affiliation: Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Ashwell
authors.affiliation: Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America.
authors.forename: Sundar
authors.initials: S
authors.lastname: Ganesan
authors.affiliation: Department of Organic Chemistry/UMYMFOR-CONICET, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Burton
authors.affiliation: Department of Biological Chemistry, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Valeria
authors.initials: V
authors.lastname: Levi
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland, United States of America.
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Hager
authors.affiliation: Department of Biological Chemistry, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina; IFIBYNE-CONICET, School of Sciences (FCEN), University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Adali
authors.initials: A
authors.lastname: Pecci
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D051379:Mice; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D011965:Receptors, Glucocorticoid / Q000737:chemistry* / Q000378:metabolism
chemical_list: D011965:Receptors, Glucocorticoid; D004247:DNA