Protein import through the nuclear pore complex is a multistep process.
Protein import through the nuclear pore complex is a multistep process.
复制标题
DOI：
10.1083/jcb.109.3.971
复制
发表时间：
1989-09
期刊：
影响因子：
--
通讯作者：
Goldfarb DS
中科院分区：
文献类型：
--
作者：
Akey CW;Goldfarb DS
核孔复合体（NPC）介导大分子物质跨核膜的转运。使用冷冻电子显微镜和图像处理，我们绘制了三个特定的金探针与NPC的相互作用，并获得了两个可能的中间体在核输入的投影图。在这些实验中使用的探针是（a）mAb-414，其与含有O-连接的N-乙酰葡糖胺的爪蟾核孔蛋白交叉反应;（B）麦胚凝集素，一种转运抑制剂;和（c）核质溶酶，一种转运底物。三种探针的强结合位点在100和125 A的半径之间的NPC上呈圆形排列，并且可以是共延的。这些结果表明，核质蛋白-金（NP-金）可以形成至少三个不同的复合物与中央运输组装的NPC，这可能是一个多步骤的蛋白质输入途径的中间体。最初，NP-金似乎在位于封闭的NPC转运体周围的多个位点结合，并且也直接在其可以停靠的中心上方结合。在随后的步骤中，NP-金通过核孔移位。
The transport of macromolecules across the nuclear envelope is mediated by the nuclear pore complex (NPC). Using cryo-electron microscopy and image processing we have mapped the interaction of three specific gold probes with the NPC and obtained projection maps of two possible intermediates in nuclear import. The probes used in these experiments were (a) mAb-414, which cross-reacts with Xenopus nucleoporins containing O-linked N-acetyl glucosamines; (b) wheat germ agglutinin, a transport inhibitor; and (c) nucleoplasmin, a transport substrate. Strong binding sites of the three probes are circularly arrayed on NPCs between radii of 100 and 125 A and may be coextensive. These results suggest that nucleoplasmin-gold (NP-gold) can form at least three distinct complexes with a central transport assembly of the NPC, which may represent intermediates of a multistep protein import pathway. Initially, NP-gold appears to bind at multiple sites located around the periphery of the closed NPC transporter and also directly over the center where it can dock. In a subsequent step NP-gold is translocated through the nuclear pore.