title: Role of ligand in retinoid signaling. 9-cis-retinoic acid modulates the oligomeric state of the retinoid X receptor.
abstract: Many of the effects of retinoids on cells are mediated by the transcription factors known as retinoid nuclear receptors, but the mechanisms by which retinoids regulate the activity of the receptors are not known. It was previously shown that the retinoid X receptor (RXR) forms tetramers with a high affinity. In the present work it is demonstrated that binding of 9-cis-retinoic acid to RXR leads to rapid dissociation of receptor tetramers. In addition, fluorescence anisotropy studies indicate that ligand-binding results in a significant conformational change such that holo-RXR is more compactly folded as compared to the apo-protein. These findings suggest that the initial event in signaling by 9-cis-retinoic acid is a change in the oligomeric state of RXR. The data also imply that tetramer formation is a regulatory feature of the pathway by which RXR mediates the effects of retinoids on gene transcription.
authors.affiliation: Cornell University, Division of Nutritional Sciences, Ithaca, New York 14853-6301, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kersten
authors.forename: L
authors.initials: L
authors.lastname: Pan
authors.forename: P
authors.initials: P
authors.lastname: Chambon
authors.forename: H
authors.initials: H
authors.lastname: Gronemeyer
authors.forename: N
authors.initials: N
authors.lastname: Noy
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005454:Fluorescence Polarization; D008024:Ligands; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D018168:Receptors, Retinoic Acid / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D047488:Retinoid X Receptors; D013388:Succinimides; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D008024:Ligands; D009687:Nuclear Proteins; D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; D047488:Retinoid X Receptors; D013388:Succinimides; D014157:Transcription Factors; C096464:disuccinimidyl glutarate; D014212:Tretinoin; D004247:DNA