title: HX531, a retinoid X receptor antagonist, inhibited the 9-cis retinoic acid-induced binding with steroid receptor coactivator-1 as detected by surface plasmon resonance.
abstract: HX531 is a retinoid X receptor (RXR) antagonist that inhibits 9-cis retinoic acid-induced neutrophilic differentiation of HL-60 cells. In order to elucidate the inhibitory mechanism of HX531, we have developed a novel ligand sensor assay for RXR in which the receptor-coactivator interaction is directly monitored using surface plasmon resonance (SPR) biosensor technology. A 20-mer peptide from steroid receptor coactivator-1 (SRC-1), containing nuclear receptor interaction motif LXXLL was immobilized on the surface of a BIAcore sensor chip. Injection of human recombinant RXR with or without 9-cis retinoic acid resulted in ligand-dependent interaction with the SRC-1 peptide. Kinetic analysis revealed dissociation constants (KD) of 9-cis RA-preincubated RXR to SRC-1 was 5.92 x 10(-8)M. Using this technique, we found that 1 microM HX531 reduced the ka value of liganded-RXR with SRC-1, suggesting that HX531 reduced the affinity of RXR to SRC-1. This SPR assay system was applied to obtain quantitative kinetic data of RXR ligand binding to the SRC-1 peptide and the alteration of these data by antagonists.
authors.affiliation: National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, 158-8501 Tokyo, Japan.
authors.forename: Toshie
authors.initials: T
authors.lastname: Kanayasu-Toyoda
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Fujino
authors.forename: Tadashi
authors.initials: T
authors.lastname: Oshizawa
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nishimaki-Mogami
authors.forename: Yoji
authors.initials: Y
authors.lastname: Sato
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Sawada
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Inoue
authors.forename: Koichi
authors.initials: K
authors.lastname: Shudo
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohno
authors.forename: Teruhide
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000077556:Alitretinoin; D001565:Benzoates / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology*; D039481:CD11b Antigen / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D051548:Histone Acetyltransferases; D009580:Nitroblue Tetrazolium; D056920:Nuclear Receptor Coactivator 1; D044042:Receptors, Formyl Peptide / Q000378:metabolism; D047488:Retinoid X Receptors / Q000819:agonists / Q000037:antagonists & inhibitors* / Q000378:metabolism; D020349:Surface Plasmon Resonance; D014157:Transcription Factors / Q000378:metabolism*; D014212:Tretinoin
chemical_list: D001565:Benzoates; D001713:Biphenyl Compounds; D039481:CD11b Antigen; D044042:Receptors, Formyl Peptide; D047488:Retinoid X Receptors; D014157:Transcription Factors; C438269:diazepinylbenzoic acid; D000077556:Alitretinoin; D009580:Nitroblue Tetrazolium; D014212:Tretinoin; D051548:Histone Acetyltransferases; C538859:NCOA1 protein, human; D056920:Nuclear Receptor Coactivator 1