Retrograde nuclear import of tRNA precursors is required for modified base biogenesis in yeast
Retrograde nuclear import of tRNA precursors is required for modified base biogenesis in yeast
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DOI：
10.1073/pnas.1105645108
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发表时间：
2011-06-28
影响因子：
11.1
通讯作者：
Suzuki, Tsutomu
中科院分区：
文献类型：
--
作者：
Ohira, Takayuki;Suzuki, Tsutomu
tRNA 从细胞质到细胞核的逆行运动在真核细胞中持续发生，但其功能意义仍不清楚。我们的证据表明，在酿酒酵母中，剪接的 tRNA 前体必须先导入细胞核，然后才能发生修饰碱基的生物合成。威布糖 (yW) 是与 tRNA(Phe) 反密码子相邻的修饰碱基，是准确解码所必需的。葡萄糖饥饿或核tRNA结合蛋白Trz1p的过度表达都会导致细胞质tRNA的核滞留，损害yW合成，并诱导其中间体N(1)-甲基鸟苷(m(1)G)的积累，表明剪接后的tRNA(Phe)被输入到细胞核，其中m(1)G由Trm5p形成，之后它被重新输出到细胞核。细胞质，其中 yW 合成由细胞质酶完成。
The retrograde movement of tRNAs from the cytoplasm to the nucleus occurs constitutively in eukaryotic cells but its functional significance remains unclear. We show evidence suggesting that in Saccharomyces cerevisiae, a spliced tRNA precursor must be imported into the nucleus before the biogenesis of a modified base can occur. Wybutosine (yW) is a modified base adjacent to the anticodon of tRNA(Phe) and is required for accurate decoding. Glucose starvation or overexpression of the nuclear tRNA binding protein Trz1p both caused nuclear retention of cytoplasmic tRNAs, impaired the yW synthesis, and induced the accumulation of its intermediate, N(1)-methylgunanosine (m(1)G), showing that the post-spliced tRNA(Phe) is imported to the nucleus, where m(1)G is formed by Trm5p, after which it is reexported to the cytoplasm, where the yW synthesis is completed by cytoplasmic enzymes.