title: 9-cis retinoic acid stereoisomer binds and activates the nuclear receptor RXR alpha.
abstract: Vitamin A (retinol) and its natural derivatives are required for many physiological processes. The activity of retinoids is thought to be mediated by interactions with two subfamilies of nuclear retinoic acid receptors, RAR and RXR. The RARs bind all-trans retinoic acid (t-RA) with high affinity and alter gene expression as a consequence of this direct ligand interaction. RXR alpha is activated by t-RA, yet has little binding affinity for this ligand. t-RA may be converted to a more proximate ligand that directly binds and activates RXR alpha, and we have developed a method of nuclear receptor-dependent ligand trapping to test this hypothesis. Here we report the identification of a stereoisomer of retinoic acid, 9-cis retinoic acid, which directly binds and activates RXR alpha. These results suggest a new role for isomerization in the physiology of natural retinoids.
authors.affiliation: Department of Toxicology, Hoffmann-La Roche, Nutley, New Jersey.
authors.forename: A A
authors.initials: AA
authors.lastname: Levin
authors.forename: L J
authors.initials: LJ
authors.lastname: Sturzenbecker
authors.forename: S
authors.initials: S
authors.lastname: Kazmer
authors.forename: T
authors.initials: T
authors.lastname: Bosakowski
authors.forename: C
authors.initials: C
authors.lastname: Huselton
authors.forename: G
authors.initials: G
authors.lastname: Allenby
authors.forename: J
authors.initials: J
authors.lastname: Speck
authors.forename: C
authors.initials: C
authors.lastname: Kratzeisen
authors.forename: M
authors.initials: M
authors.lastname: Rosenberger
authors.forename: A
authors.initials: A
authors.lastname: Lovey
mesh_terms: D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction / Q000379:methods; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D013237:Stereoisomerism; D014158:Transcription, Genetic; D014162:Transfection; D014212:Tretinoin / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; D014212:Tretinoin