MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA; Plant Biology Department, Michigan State University, East Lansing, MI 48824, USA.
MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA.
Cell Rep. 2018 May 22;23(8):2299-2307. doi: 10.1016/j.celrep.2018.04.091.
Through yet-undefined mechanisms, the plant endoplasmic reticulum (ER) has a critical role in endocytosis. The plant ER establishes a close association with endosomes and contacts the plasma membrane (PM) at ER-PM contact sites (EPCSs) demarcated by the ER membrane-associated VAMP-associated-proteins (VAP). Here, we investigated two plant VAPs, VAP27-1 and VAP27-3, and found an interaction with clathrin and a requirement for the homeostasis of clathrin dynamics at endocytic membranes and endocytosis. We also demonstrated direct interaction of VAP27-proteins with phosphatidylinositol-phosphate lipids (PIPs) that populate endocytic membranes. These results support that, through interaction with PIPs, VAP27-proteins bridge the ER with endocytic membranes and maintain endocytic traffic, likely through their interaction with clathrin.
通过尚未明确的机制,植物内质网(ER)在胞吞作用中起着关键作用。植物 ER 与内体建立密切联系,并通过内质网膜相关 VAMP 相关蛋白(VAP)标记的内质网-质膜接触位点(EPCs)与质膜(PM)接触。在这里,我们研究了两种植物 VAP,VAP27-1 和 VAP27-3,并发现与网格蛋白的相互作用以及网格蛋白动力学在内质网和胞吞作用中的内稳态的需求。我们还证明了 VAP27 蛋白与富含胞吞膜的磷脂酰肌醇磷酸脂质(PIPs)的直接相互作用。这些结果表明,通过与 PIPs 的相互作用,VAP27 蛋白将 ER 与胞吞膜桥接,并维持胞吞作用,可能通过与网格蛋白的相互作用。