title: Spatiotemporal Dynamics of the BRI1 Receptor and its Regulation by Membrane Microdomains in Living Arabidopsis Cells.
abstract: The major brassinosteroid (BR) receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 (BRI1) plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization and assembly state remain unclear. Here, we applied variable angle total internal reflection fluorescence microscopy and fluorescence cross-correlation spectroscopy to analyze the dynamics of GFP-tagged BRI1. We found that, in response to BR, the degree of co-localization of BRI1-GFP with AtFlot1-mCherry increased, and especially BR stimulated the membrane microdomain-associated pathway of BRI1 internalization. We also verified these observations in endocytosis-defective chc2-1 mutants and the AtFlot1 amiRNA 15-5 lines. Furthermore, examination of the phosphorylation status of bri1-EMS-suppressor 1 and measurement of BR-responsive gene expression revealed that membrane microdomains affect BR signaling. These results suggest that BR promotes the partitioning of BRI1 into functional membrane microdomains to activate BR signaling.
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Lv
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Ruili
authors.initials: R
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Xue
authors.affiliation: State Key Laboratory of Genetic Engineering and Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Jin
authors.affiliation: Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany.
authors.forename: František
authors.initials: F
authors.lastname: Baluška
authors.affiliation: Department of Cell Biology, Palacky University Olomouc, Olomouc 78371, Czech Republic.
authors.forename: Jozef
authors.initials: J
authors.lastname: Šamaj
authors.affiliation: State Key Laboratory of Genetic Engineering and Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China; College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xuelu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China. Electronic address: linjinxing@bjfu.edu.cn.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Lin
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D060406:Brassinosteroids / Q000494:pharmacology; D002966:Clathrin / Q000378:metabolism; D004058:Diffusion; D004705:Endocytosis / Q000187:drug effects; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism*; D009038:Motion; D059828:Plant Cells / Q000187:drug effects / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D055503:Protein Multimerization / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D062211:Spatio-Temporal Analysis
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002966:Clathrin; D011494:Protein Kinases; C108270:BRI1 protein, Arabidopsis
keywords: BR signaling; BRI1; endocytosis; membrane microdomains; spatiotemporal dynamics