Scyl1 facilitates nuclear tRNA export in mammalian cells by acting at the nuclear pore complex.
Scyl1 facilitates nuclear tRNA export in mammalian cells by acting at the nuclear pore complex.
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DOI：
10.1091/mbc.e10-03-0176
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发表时间：
2010-07-15
影响因子：
3.3
通讯作者：
Mangroo D
中科院分区：
文献类型：
--
作者：
Chafe SC;Mangroo D
我们提供的证据表明，Scyl1也是核氨酰化依赖的tRNA输出途径的细胞质成分。Scyl1和酿酒酵母Cex1p一样，可以从鼻咽癌胞质侧的核tRNA输出受体收集氨基酰tRNA，并将它们引导到EEF-1A用于蛋白质合成。Scyl1是一种进化上保守的N末端蛋白激酶样结构域蛋白，在COP1介导的哺乳动物细胞逆行蛋白转运中发挥作用。此外，Scyl1功能的丧失已被证明会导致小鼠的神经退行性疾病。在这里，我们报告Scyl1也是哺乳动物核tRNA输出机制的细胞质成分。与exportin-t一样，Scyl1的过表达恢复了COS-7细胞中核出口缺陷的丝氨酸琥珀抑制因子tRNA突变体的出口。Scyl1饱和地与tRNA结合，并通过部分与Nup98相互作用与核孔复合体结合。Scyl1与核tRNA出口受体exportin-t和exportin-5、RanGTP酶和真核细胞的延伸因子EEF-1A结合，后者将氨酰-tRNA运输到核糖体。Scyl1在体外与Exportin-t和RanGTP直接相互作用，但不与EEF-1A或RanGDP相互作用。此外，含有tRNA、Scyl1和RanGTP的exportin-t在体外形成四元复合体。生化特征还表明，依赖于核氨酰化的途径是哺乳动物细胞中tRNA输出的主要原因。这些发现表明，Scyl1参与了依赖于核氨酰化的tRNA输出途径，并可能从核孔复合体细胞质一侧的核tRNA输出受体上卸载氨酰tRNA，并将它们输送到EEF-1A。
We provide evidence that Scyl1 is also a cytoplasmic component of the nuclear aminoacylation-dependent tRNA export pathway. Scyl1, like the Saccharomyces cerevisiae Cex1p, may collect aminoacyl-tRNAs from the nuclear tRNA export receptors at the cytoplasmic side of the NPC and channel them to eEF-1A for use in protein synthesis. Scyl1 is an evolutionarily conserved N-terminal protein kinase-like domain protein that plays a role in COP1-mediated retrograde protein trafficking in mammalian cells. Furthermore, loss of Scyl1 function has been shown to result in neurodegenerative disorders in mice. Here, we report that Scyl1 is also a cytoplasmic component of the mammalian nuclear tRNA export machinery. Like exportin-t, overexpression of Scyl1 restored export of a nuclear export-defective serine amber suppressor tRNA mutant in COS-7 cells. Scyl1 binds tRNA saturably, and associates with the nuclear pore complex by interacting, in part, with Nup98. Scyl1 copurifies with the nuclear tRNA export receptors exportin-t and exportin-5, the RanGTPase, and the eukaryotic elongation factor eEF-1A, which transports aminoacyl-tRNAs to the ribosomes. Scyl1 interacts directly with exportin-t and RanGTP but not with eEF-1A or RanGDP in vitro. Moreover, exportin-t containing tRNA, Scyl1, and RanGTP form a quaternary complex in vitro. Biochemical characterization also suggests that the nuclear aminoacylation-dependent pathway is primarily responsible for tRNA export in mammalian cells. These findings together suggest that Scyl1 participates in the nuclear aminoacylation-dependent tRNA export pathway and may unload aminoacyl-tRNAs from the nuclear tRNA export receptor at the cytoplasmic side of the nuclear pore complex and channels them to eEF-1A.
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影响因子：
3.3
作者：
Bernstein, KA;Baserga, SJ
通讯作者：
Baserga, SJ
影响因子：
5.3
作者：
Drabkin, HJ;Rajbhandary, UL
通讯作者：
Rajbhandary, UL
影响因子：
4.1
作者：
Kruse, C;Willkomm, DK;Müller, PK
通讯作者：
Müller, PK
DOI：
10.1083/jcb.149.3.567
发表时间：
2000-05-01
期刊：
The Journal of cell biology
影响因子：
--
作者：
Ko YG;Kang YS;Kim EK;Park SG;Kim S
通讯作者：
Kim S
影响因子：
16
作者：
Kutay, U;Lipowsky, G;Gorlich, D
通讯作者：
Gorlich, D