Thio-modification of yeast cytosolic tRNA requires a ubiquitin-related system that resembles bacterial sulfur transfer systems
Thio-modification of yeast cytosolic tRNA requires a ubiquitin-related system that resembles bacterial sulfur transfer systems
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DOI：
10.1074/jbc.m804043200
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发表时间：
2008-10-10
影响因子：
4.8
通讯作者：
Hayashi, Hideyuki
中科院分区：
文献类型：
--
作者：
Nakai, Yumi;Nakai, Masato;Hayashi, Hideyuki
酵母胞浆Trn(Uuu)(Alys2)和tRNA(Uuc)(Glu3)中的摆动尿苷在第二位发生硫代修饰(S(2)修饰)，在第五位发生甲氧基甲基化修饰(mcm(5)修饰)。我们以前证明了胞质和线粒体铁硫(Fe/S)簇组装机制被称为CIA和ISC，包括一种名为NFS1的半胱氨酸脱硫酶，是S(2)修饰所必需的。然而，直接参与这一过程的胞浆成分仍不清楚。我们发现，S(2)的修饰严格需要泛素样蛋白Urm1和泛素激活酶样蛋白Uba4，以及Tuc1和Tuc2。URM1的羧基末端甘氨酸残基对于S(2)的修饰是关键的，这表明独特的泛素相关系统直接参与了这一过程。我们还证明了胞质tRNA中的S(2)和mcm(5)修饰相互影响彼此的效率。综上所述，我们的数据表明，细胞质tRNA的S(2)修饰是一个更复杂的过程，需要额外的未知成分。
The wobble uridine in yeast cytosolic tRN(UUU)(ALys2) and tRNA(UUC)(Glu3) undergoes a thio- modification at the second position (s(2) modification) and a methoxycarbonylmethyl modification at the fifth position (mcm(5) modification). We previously demonstrated that the cytosolic and mitochondrial iron- sulfur (Fe/S) cluster assembly machineries termed CIA and ISC, including a cysteine desulfurase called Nfs1, were essential for the s(2) modification. However, the cytosolic component that directly participates in this process remains unclear. Wefound that ubiquitinlike protein Urm1 and ubiquitin- activating enzyme- like protein Uba4, as well as Tuc1 and Tuc2, were strictly required for the s(2) modification. The carboxyl- terminal glycine residue of Urm1 was critical for the s(2) modification, indicating direct involvement of the unique ubiquitin- related system in this process. We also demonstrated that the s(2) and mcm(5) modifications in cytosolic tRNAs influence each other's efficiency. Taken together, our data indicate that the s(2) modification of cytosolic tRNAs is a more complex process that requires additional unidentified components.