植物重要膜蛋白的扩散与胞吞机制

Dynamics and endocytosis of important membrane proteins in plants

膜蛋白作为细胞膜的重要组成部分,通常会发生胞吞循环以调控其在细胞膜上的数量平衡,或响应外界环境的刺激.单分子成像技术是近年来发展起来的,可用于在活细胞条件下对单个分子进行观测和研究的新技术,具有较高的时空分辨率,实现了在纳米和微秒水平上对单个分子的快速实时成像和精确分析.本文结合作者所在实验室取得的研究成果,介绍了利用单分子技术,包括全内反射荧光显微术、荧光相关光谱、荧光互相关光谱分析等方法,对植物几种重要膜蛋白在质膜上的运动特征以及胞吞途径的研究工作,总结了植物中脂筏微区分布及脂筏参与的胞吞途径对膜蛋白功能的调控机制,展望了植物质膜微区的精确划分以及膜蛋白胞吞之后的去向等方面所面临的难题.

Membrane proteins represent important constituents of plasma membranes and serve biological functions. These proteins regulate endocytic recycling to control the abundance and distribution of proteins at the cell surface, and transduce signals from the extracellular environment to the intracellular space. Single-molecule techniques directly monitor the rapid nanometer-scale spatiotemporal dynamics of molecules and are especially suitable to analyse molecular behaviors in living cells. In this review, we outline the principles of single-molecule microscopy and spectroscopy techniques, and highlight the importance of using these techniques in the study of plant membrane proteins. We summarize the motion characteristics in relation to the endocytic pathways of plasma membrane proteins and highlight the role of lipid rafts and the regulation mechanisms of PM proteins. Furthermore, existing problems and future challenges of this new field are discussed, e.g., the accurate separation of membrane microdomains and the fate of endocytic proteins.