Membrane microdomains and the cytoskeleton constrain At HIR 1 dynamics and facilitate the formation of an At HIR 1‐associated immune complex

作者：Xueqin Lv, Yanping Jing, Jianwei Xiao, Yongdeng Zhang, Yingfang Zhu, Russell Julian, Jinxing Lin · 发表于：The Plant Journal · 年份：2017 · DOI：10.1111/tpj.13480 · 被引用次数：106 · 研究领域：Plant-Microbe Interactions and Immunity、Polysaccharides and Plant Cell Walls、Plant Stress Responses and Tolerance

Arabidopsis hypersensitive-induced reaction (AtHIR) proteins function in plant innate immunity. However, the underlying mechanisms by which AtHIRs participate in plant immunity remain elusive. Here, using VA-TIRFM and FLIM-FRET, we revealed that AtHIR1 is present in membrane microdomains and co-localizes with the membrane microdomain marker REM1.3. Single-particle tracking analysis revealed that membrane microdomains and the cytoskeleton, especially microtubules, restrict the lateral mobility of AtHIR1 at the plasma membrane and facilitate its oligomerization. Furthermore, protein proximity index measurements, fluorescence cross-correlation spectroscopy, and biochemical experiments demonstrated that the formation of the AtHIR1 complex upon pathogen perception requires intact microdomains and cytoskeleton. Taken together, these findings suggest that microdomains and the cytoskeleton constrain AtHIR1 dynamics, promote AtHIR1 oligomerization, and increase the efficiency of the interactions of AtHIR1 with components of the AtHIR1 complex in response to pathogens, thus providing valuable insight into the mechanisms of defense-related responses in plants.