Spatiotemporal Dynamics of the BRI1 Receptor and its Regulation by Membrane Microdomains in Living Arabidopsis Cells

Li Wang; Hong Li; Xueqin Lv; Tong Chen; Ruili Li; Yiqun Xue; Jianjun Jiang; Biao Jin; František Baluška; Jozef Šamaj; Xuelu Wang; Jinxing Lin

doi:10.1016/j.molp.2015.04.005

Spatiotemporal Dynamics of the BRI1 Receptor and its Regulation by Membrane Microdomains in Living Arabidopsis Cells

Mol Plant. 2015 Sep;8(9):1334-49. doi: 10.1016/j.molp.2015.04.005. Epub 2015 Apr 18.

Authors

Li Wang¹, Hong Li¹, Xueqin Lv², Tong Chen³, Ruili Li⁴, Yiqun Xue³, Jianjun Jiang⁵, Biao Jin⁶, František Baluška⁷, Jozef Šamaj⁸, Xuelu Wang⁹, Jinxing Lin¹⁰

Affiliations

¹ 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.
² 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.
³ Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
⁴ College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
⁵ State Key Laboratory of Genetic Engineering and Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China.
⁶ College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China.
⁷ Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany.
⁸ Department of Cell Biology, Palacky University Olomouc, Olomouc 78371, Czech Republic.
⁹ 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.
¹⁰ 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.

PMID: 25896454
DOI: 10.1016/j.molp.2015.04.005

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.

Keywords: BR signaling; BRI1; endocytosis; membrane microdomains; spatiotemporal dynamics.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arabidopsis / cytology*
Arabidopsis / metabolism*
Arabidopsis Proteins / metabolism*
Brassinosteroids / pharmacology
Clathrin / metabolism
Diffusion
Endocytosis / drug effects
Membrane Microdomains / drug effects
Membrane Microdomains / metabolism*
Motion
Plant Cells / drug effects
Plant Cells / metabolism*
Protein Kinases / metabolism*
Protein Multimerization / drug effects
Signal Transduction / drug effects
Spatio-Temporal Analysis*

Substances

Arabidopsis Proteins
Brassinosteroids
Clathrin
Protein Kinases
BRI1 protein, Arabidopsis