Naim Bracha, Zbaida David, Dagan Shlomi, Kapon Ruti, Reich Ziv
Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
EMBO J. 2009 Sep 16;28(18):2697-705. doi: 10.1038/emboj.2009.225. Epub 2009 Aug 13.
To fulfil their function, nuclear pore complexes (NPCs) must discriminate between inert proteins and nuclear transport receptors (NTRs), admitting only the latter. This specific permeation is thought to depend on interactions between hydrophobic patches on NTRs and phenylalanine-glycine (FG) or related repeats that line the NPC. Here, we tested this premise directly by conjugating different hydrophobic amino-acid analogues to the surface of an inert protein and examining its ability to cross NPCs unassisted by NTRs. Conjugation of as few as four hydrophobic moieties was sufficient to enable passage of the protein through NPCs. Transport of the modified protein proceeded with rates comparable to those measured for the innate protein when bound to an NTR and was relatively insensitive both to the nature and density of the amino acids used to confer hydrophobicity. The latter observation suggests a non-specific, small, and plant interaction network between cargo and FG repeats.
为履行其功能，核孔复合体（NPC）必须区分惰性蛋白质和核转运受体（NTR），只允许后者进入。这种特异性渗透被认为取决于NTR上的疏水区域与NPC内衬的苯丙氨酸-甘氨酸（FG）或相关重复序列之间的相互作用。在这里，我们通过将不同的疏水氨基酸类似物与惰性蛋白质表面偶联，并检查其在无NTR协助下穿过NPC的能力，直接测试了这一前提。仅偶联四个疏水部分就足以使蛋白质通过NPC。修饰后的蛋白质的转运速率与结合NTR时天然蛋白质的测量速率相当，并且对用于赋予疏水性的氨基酸的性质和密度相对不敏感。后一观察结果表明货物与FG重复序列之间存在非特异性、小且的相互作用网络。 （注：原文中“small, and plant interaction network”表述似乎有误，推测可能是“small and specific interaction network”，翻译时按推测内容翻译了，供你参考。）
