Lord Christopher L, Timney Benjamin L, Rout Michael P, Wente Susan R
Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232.
Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY 10021.
J Cell Biol. 2015 Mar 16;208(6):729-44. doi: 10.1083/jcb.201412024.
The eukaryotic nuclear permeability barrier and selective nucleocytoplasmic transport are maintained by nuclear pore complexes (NPCs), large structures composed of ∼ 30 proteins (nucleoporins [Nups]). NPC structure and function are disrupted in aged nondividing metazoan cells, although it is unclear whether these changes are a cause or consequence of aging. Using the replicative life span (RLS) of Saccharomyces cerevisiae as a model, we find that specific Nups and transport events regulate longevity independent of changes in NPC permeability. Mutants lacking the GLFG domain of Nup116 displayed decreased RLSs, whereas longevity was increased in nup100-null mutants. We show that Nup116 mediates nuclear import of the karyopherin Kap121, and each protein is required for mitochondrial function. Both Kap121-dependent transport and Nup116 levels decrease in replicatively aged yeast. Overexpression of GSP1, the small GTPase that powers karyopherin-mediated transport, rescued mitochondrial and RLS defects in nup116 mutants and increased longevity in wild-type cells. Together, these studies reveal that specific NPC nuclear transport events directly influence aging.
真核细胞核通透屏障和选择性核质运输由核孔复合体(NPC)维持,核孔复合体是由约30种蛋白质(核孔蛋白 [Nup])组成的大型结构。在衰老的非分裂后生动物细胞中,NPC的结构和功能会受到破坏,尽管尚不清楚这些变化是衰老的原因还是结果。以酿酒酵母的复制寿命(RLS)为模型,我们发现特定的核孔蛋白和运输事件独立于NPC通透性的变化来调节寿命。缺乏Nup116的GLFG结构域的突变体显示出复制寿命缩短,而nup100缺失突变体的寿命则延长。我们表明,Nup116介导核转运蛋白Kap121的核输入,并且这两种蛋白质都是线粒体功能所必需的。在复制衰老的酵母中,依赖Kap121的运输和Nup116水平都会降低。为核转运蛋白介导的运输提供动力的小GTP酶GSP1的过表达挽救了nup116突变体中的线粒体和复制寿命缺陷,并延长了野生型细胞的寿命。总之,这些研究表明特定的NPC核运输事件直接影响衰老。