title: Immunophilin-like FKBP42/TWISTED DWARF1 Interacts with the Receptor Kinase BRI1 to Regulate Brassinosteroid Signaling in Arabidopsis.
abstract: Mutation of the immunophilin-like FK506-binding protein TWISTED DWARF1 (FKBP42/TWD1) causes dwarf and twisted-organ phenotypes in Arabidopsis. However, the function of FKBP42 is not fully understood at the molecular level. Using genetic, physiological, and immunological experiments, we show here that FKBP42/TWD1 is necessary for brassinosteroid (BR) signal transduction. The twd1 mutant showed reduced BR sensitivity in growth responses and activation of the BZR1 transcription factor. However, twd1 showed normal responses to an inhibitor of BIN2/GSK3, suggesting that twd1 has a defect upstream of BIN2 in the BR signaling pathway. In vitro and in vivo assays showed that TWD1 interacts physically with the kinase domains of the BR receptor kinases BRI1 and BAK1. TWD1 is not required for normal localization of BRI1-GFP to the plasma membrane or for activation of the flagellin receptor kinase FLS2. Our results suggest that FKBP42/TWD1 plays a specific role in the activation of BRI1 receptor kinase.
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Botany, Center of Excellence in Environment and Plant Physiology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
authors.forename: Juthamas
authors.initials: J
authors.lastname: Chaiwanon
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
authors.forename: Veder J
authors.initials: VJ
authors.lastname: Garcia
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
authors.forename: Heather
authors.initials: H
authors.lastname: Cartwright
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA. Electronic address: zywang24@stanford.edu.
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D009154:Mutation; D011485:Protein Binding; D000072417:Protein Domains; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism; D021381:Protein Transport; D015398:Signal Transduction; D022021:Tacrolimus Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; C471286:TWD1 protein, Arabidopsis; D011494:Protein Kinases; C463660:BAK1 protein, Arabidopsis; C108270:BRI1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D022021:Tacrolimus Binding Proteins
keywords: BRI1; FKBP42; brassinosteroid signaling