Dannhauser Philip N, Platen Mitja, Böning Heike, Ungewickell Huberta, Schaap Iwan A T, Ungewickell Ernst J
Institute of Cell Biology, Centre of Anatomy, Hannover Medical School, Carl-Neuberg Street 1, D-30625, Hannover, Germany.
Traffic. 2015 May;16(5):519-33. doi: 10.1111/tra.12263. Epub 2015 Feb 24.
Clathrin-dependent transport processes require the polymerization of clathrin triskelia into polygonal scaffolds. Together with adapter proteins, clathrin collects cargo and induces membrane bud formation. It is not known to what extent clathrin light chains affect the structural and functional properties of clathrin lattices and the ability of clathrin to deform membranes. To address these issues, we have developed a novel procedure for analyzing clathrin lattice formation on rigid surfaces. We found that lattices can form on adaptor-coated convex-, planar- and even shallow concave surfaces, but the rate of formation and resistance to thermal dissociation of the lattice are greatly enhanced on convex surfaces. Atomic force microscopy on planar clathrin lattices demonstrates that the stiffness of the clathrin lattice is strictly dependent on light chains. The reduced stiffness of the lattice also compromised the ability of clathrin to generate coated buds on the surface of rigid liposomal membranes.
网格蛋白依赖的运输过程需要网格蛋白三脚复合体聚合成多边形支架。网格蛋白与衔接蛋白一起收集货物并诱导膜芽形成。目前尚不清楚网格蛋白轻链在多大程度上影响网格蛋白晶格的结构和功能特性以及网格蛋白使膜变形的能力。为了解决这些问题，我们开发了一种用于分析刚性表面上网格蛋白晶格形成的新方法。我们发现晶格可以在衔接蛋白包被的凸面、平面甚至浅凹面上形成，但在凸面上晶格的形成速率和对热解离的抗性大大提高。对平面网格蛋白晶格的原子力显微镜观察表明，网格蛋白晶格的刚度严格依赖于轻链。晶格刚度的降低也损害了网格蛋白在刚性脂质体膜表面产生包被小芽的能力。
