CHARACTERIZATION OF THE NUCLEAR PORECOMPLEX OF THE AFRICAN TRYPANOSOME

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 核孔复合体(NPC)是真核生物所特有的一种巨大的大分子组合体，它介导了核质之间的双向物质交换。直到最近，NPC的进化起源还不清楚，这给我们对真核生物起源的理解留下了很大的空白。先前的生物信息学研究得出的结论是，最后一个共同的真核祖先(LCEA)拥有一个相当原始的鼻咽癌祖先，向其高度分化的现代后代传递的成分很少。使用蛋白质组/基因组学方法，我们证明了LCEA实际上拥有一个具有令人惊讶的现代结构的NPC。此外，我们已经确定，所有的NPC都有一个基本相似的支架结构，类似于涂层囊泡的结构。我们的发现有力地支持了这样一种假设，即神经干细胞与囊泡涂层复合体有着共同的祖先，并且两者都是在真核进化的非常早期就建立起来的。描述这项工作的手稿已经出版(23.J.A.deGrasse，K.N.Dubois，D.Devos，T.N.Siegel，A.Sali，M.C.field，M.P.Rout，B.T.Chait“从最后一个共同的真核生物祖先”分子和细胞蛋白质组学“，8(2009)2119-30保守的共享核孔复合体结构的证据。 我们现在正在继续改进我们的亲和分离程序，以获得关于结构、功能和T.brucei NPC进化的更高分辨率的信息，并正在获得非常有希望的结果。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The nuclear pore complex (NPC) is a massive macromolecular assembly, unique to Eukaryotes, that mediates bidirectional exchange of material between the nucleus and cytoplasm. Until recently, the evolutionary origin of the NPC was unknown, leaving a major gap in our understanding of the origin of the Eukaryota. Prior bioinformatic studies led to the conclusion that the Last Common Eukaryotic Ancestor (LCEA) possessed a rather primitive ancestral NPC, passing few components to its highly divergent modern descendants. Using a proteomic/genomic approach, we show that the LCEA actually possessed an NPC with a surprisingly modern architecture. Moreover, we have established that all NPCs have a fundamentally similar scaffold architecture that resembles the architecture of coated vesicles. Our findings strongly support the hypothesis that NPCs share a common ancestry with vesicle coating complexes, and that both were established very early in eukaryotic evolution. A manuscript describing this work has been published (23. J.A. DeGrasse, K.N. DuBois, D. Devos, T.N. Siegel, A. Sali, M.C. Field, M.P. Rout, B.T. Chait "Evidence for a shared nuclear pore complex architecture that is conserved from the last common eukaryotic ancestor" Molecular & Cellular Proteomics, 8 (2009) 2119-30). We are now continuing to improve our affinity isolation procedures for gaining higher resolution information about the architecture, function an evolution of the T. brucei NPC and are obtaining very promising results.