Mapping nuclear pore surface with atomic force microscopy

核孔复合体是跨越真核细胞核膜的蛋白质超分子集合体。离子和大分子的运输是通过这种途径进行的。目前尚不清楚不同货物是否存在不同的路线，以及通往这些路线的途径是否取决于NPC表面的疏水性质。通过使用原子力显微镜(AFM)绘制鼻咽癌表面图，解决了这个悬而未决的问题。将使用具有不同疏水或亲水性质的AFM针尖，以窄行间距执行对单个NPC的表面扫描。从AFM针尖与NPC表面的相互作用(即粘附力)出发，检验了NPC表面是否包含将运输路线划分为无机离子运输路线(亲水路线)、小有机大分子运输路线(两亲性路线)和使用中央通道的大货物运输路线(疏水路线)的区域。电导和荧光葡聚糖测量的组合将被用来选择性地定位单独的通路。通过对鼻咽癌表面的高分辨率原子力显微镜成像，我们将寻找鼻咽癌周围假设的外周通道。该项目的目标是更好地了解单个鼻咽癌一级的核转移过程。

Nuclear pore complexes (NPCs) are supramolecular assemblies of proteins that span the nuclear envelope of eukaryotic cells. Transport of ions and macromolecules occurs through this pathway. It is still unclear whether different routes exist for different cargos and whether the access to such routes depends on the hydrophobic properties of the NPC surface. This open question is addressed by NPC surface mapping using atomic force microscopy (AFM). Surface scans across individual NPCs will be performed with narrow line spacing using AFM tips with different hydrophobic or hydrophilic properties. Derived from the AFM tip interaction with the NPC surface (i.e. adhesion forces) the hypothesis is tested whether the NPC surface consists of zones that separate transport routes into one for inorganic ions (hydrophilic route), one for small organic macromolecules (amphiphilic route) and one for large cargo using the central channel (hydrophobic route). A combination of electrical conductance and fluorescent dextran measurements will be used to selectively localize the individual pathways. With high resolution AFM imaging of the NPC surface we will search for the postulated peripheral channels in the NPC periphery. The goal of the project is a better understanding of nuclear translocation processes at the single NPC level.