State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China.
Plant Physiol. 2024 Nov 4;196(3):1813-1825. doi: 10.1093/plphys/kiae403.
Plasma membranes (PMs) are highly dynamic structures where lipids and proteins can theoretically diffuse freely. However, reports indicate that PM proteins do not freely diffuse within their planes but are constrained by cytoskeleton networks, though the mechanisms for how the cytoskeleton restricts lateral diffusion of plant PM proteins are unclear. Through single-molecule tracking, we investigated the dynamics of 6 Arabidopsis (Arabidopsis thaliana) PM proteins with diverse structures and found distinctions in sizes and dynamics among these proteins. Moreover, we showed that the cytoskeleton, particularly microtubules, limits the diffusion of PM proteins, including transmembrane and membrane-anchoring proteins. Interestingly, the microfilament skeleton regulates intracellular transport of endocytic cargo. Therefore, these findings indicate that the cytoskeleton controls signal transduction by limiting diffusion of PM proteins in specific membrane compartments and participating in transport of internalized cargo vesicles, thus actively regulating plant signal transduction.
质膜(PM)是高度动态的结构,脂质和蛋白质在理论上可以自由扩散。然而,有报道称,PM 蛋白在其平面内不能自由扩散,而是受到细胞骨架网络的限制,尽管细胞骨架限制植物 PM 蛋白侧向扩散的机制尚不清楚。通过单分子追踪,我们研究了具有不同结构的 6 种拟南芥(Arabidopsis thaliana)PM 蛋白的动力学,发现这些蛋白的大小和动力学存在差异。此外,我们还表明,细胞骨架,特别是微管,限制了 PM 蛋白的扩散,包括跨膜和膜锚定蛋白。有趣的是,微丝骨架调节内吞货物的细胞内运输。因此,这些发现表明,细胞骨架通过限制特定膜区室中 PM 蛋白的扩散以及参与内化货物囊泡的运输来控制信号转导,从而积极调节植物信号转导。