Two novel related yeast nucleoporins Nup170p and Nup157p: complementation with the vertebrate homologue Nup155p and functional interactions with the yeast nuclear pore-membrane protein Pom152p.
Two novel related yeast nucleoporins Nup170p and Nup157p: complementation with the vertebrate homologue Nup155p and functional interactions with the yeast nuclear pore-membrane protein Pom152p.
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DOI：
10.1083/jcb.131.5.1133
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发表时间：
1995-12
期刊：
影响因子：
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通讯作者：
Wozniak RW
中科院分区：
文献类型：
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作者：
Aitchison JD;Rout MP;Marelli M;Blobel G;Wozniak RW
我们已经采取了遗传和生物化学相结合的方法来确定酵母核孔复合物（NPC）的主要成分。一个合成的致死筛选被用来识别蛋白质的主要孔膜蛋白Pom152p的遗传相互作用。平行地，在高度富集的酵母NPC制剂中以与Pom152p相似的量存在的多肽已经通过直接微测序表征。这些方法导致了两个新的和主要的核孔蛋白，Nup170p和Nup157p的鉴定。Nup170 p和Nup157 p彼此相似，并且与丰富的哺乳动物核孔蛋白Nup155 p相似（Radu，A.，G. Blobel和R. W.沃兹尼亚克1993. 121：1 - 9），并且有趣的是，nup170突变体可以与哺乳动物NUP155互补。此外，合成致死筛选鉴定了Pom152p和另外两种主要核孔蛋白Nup188p之间的遗传相互作用（Nehrbass，U.，S. Maguire，M. Rout，G. Blobel和R. W.沃兹尼亚克，手稿已提交出版）和Nic 96 p（Grandi，P.，V. Doye和E. C.受伤了1993. 12：3061 - 71）。我们已经确定，Nup170p、Nup157p、Pom152p、Nup188p和Nic96p共同构成了分离的酵母NPC质量的五分之一以上。对这些蛋白质之间的遗传相互作用的检查表明，虽然单独缺失POM 152、NUP170或NUP188不是致命的，但成对组合是致命的。NUP157的缺失也不是致命的。然而，nup157无效突变体，而致命的组合nup170和nup188无效等位基因，是不是合成致死pom152无效等位基因。我们认为Nup170p和Nup157p可能是酵母NPC的形态对称但功能不同的亚结构的一部分，例如，核质环和细胞质环。最后，我们观察到形态异常的核膜作为NUP170的表达水平的变化的函数，这表明NPC组分之间的特定化学计量关系是维持正常核结构所必需的。
We have taken a combined genetic and biochemical approach to identify major constituents of the yeast nuclear pore complex (NPC). A synthetic lethal screen was used to identify proteins which interact genetically with the major pore-membrane protein Pom152p. In parallel, polypeptides present in similar amounts to Pom152p in a highly enriched preparation of yeast NPCs have been characterized by direct microsequencing. These approaches have led to the identification of two novel and major nucleoporins, Nup170p and Nup157p. Both Nup170p and Nup157p are similar to each other and to an abundant mammalian nucleoporin, Nup155p (Radu, A., G. Blobel, and R. W. Wozniak. 1993. J. Cell Biol. 121: 1-9) and interestingly, nup170 mutants can be complemented with mammalian NUP155. In addition, the synthetic lethal screen identified genetic interactions between Pom152p and two other major nucleoporins, Nup188p (Nehrbass, U., S. Maguire, M. Rout, G. Blobel, and R. W. Wozniak, manuscript submitted for publication), and Nic96p (Grandi, P., V. Doye, and E. C. Hurt. 1993. EMBO J. 12: 3061-71). We have determined that together, Nup170p, Nup157p, Pom152p, Nup188p, and Nic96p comprise greater than one-fifth of the mass of the isolated yeast NPC. Examination of the genetic interactions between these proteins indicate that while deletion of either POM152, NUP170, or NUP188 alone is not lethal, pairwise combinations are. Deletion of NUP157 is also not lethal. However, nup157 null mutants, while lethal in combination with nup170 and nup188 null alleles, are not synthetically lethal with pom152 null alleles. We suggest that Nup170p and Nup157p may be part of a morphologically symmetrical but functionally distinct substructure of the yeast NPC, e.g., the nucleoplasmic and cytoplasmic rings. Finally, we observed morphological abnormalities in the nuclear envelope as a function of alterations in the expression levels of NUP170 suggesting a specific stoichiometric relationship between NPC components is required for the maintenance of normal nuclear structure.