Retrograde movement of tRNAs from the cytoplasm to the nucleus in Saccharomyces cerevisiae
Retrograde movement of tRNAs from the cytoplasm to the nucleus in Saccharomyces cerevisiae
复制标题
DOI：
10.1073/pnas.0503836102
复制
发表时间：
2005-08-09
影响因子：
11.1
通讯作者：
Hopper, AK
中科院分区：
文献类型：
--
作者：
Shaheen, HH;Hopper, AK
在真核生物中，核转录的tRNAs在细胞质蛋白质合成中起作用。Ran-GTP结合的exportin、Los1p/Xpo-t和附加途径(S)介导tRNA向细胞质的转运。尽管tRNA的运动被认为是单向的，但最近的报道表明，酵母前体tRNA的剪接发生在细胞质中，而完全剪接的tRNA可以驻留在细胞核中，这要求前体tRNA剪接机制或成熟的tRNA从细胞质移动到细胞核。我们的数据反对第一种可能性，并强烈支持第二种可能性。结合异核体分析和荧光原位杂交，我们发现一个核编码的外源tRNA可以从细胞质移动到第二个不编码tRNA的核。我们还发现，在单倍体酵母细胞中，内源胞质tRNAs在营养缺乏的反应下发生了核积累。胞质tRNA的核积累需要RAN和Importin-P家族的Mtr10/Kap111成员。逆行tRNA核导入可能为真核细胞基因表达调控提供一种新的机制。
In eukaryotes, tRNAs transcribed in the nucleus function in cytoplasmic protein synthesis. The Ran-GTP-binding exportin, Los1p/Xpo-t, and additional pathway(s) mediate tRNA transport to the cytoplasm. Although tRNA movement was thought to be unidirectional, recent reports that yeast precursor tRNA splicing occurs in the cytoplasm, whereas fully spliced tRNAs can reside in the nucleus, require that either the precursor tRNA splicing machinery or mature tRNAs move from the cytoplasm to the nucleus. Our data argue against the first possibility and strongly support the second. Combining heterokaryon analysis with fluorescence in situ hybridization, we show that a foreign tRNA encoded by one nucleus can move from the cytoplasm to a second nucleus that does not encode the tRNA. We also discovered nuclear accumulation of endogenous cytoplasmic tRNAs in haploid yeast cells in response to nutritional deprivation. Nuclear accumulation of cytoplasmic tRNA requires Ran and the Mtr10/Kap111 member of the importin-P family. Retrograde tRNA nuclear import may provide a novel mechanism to regulate gene expression in eukaryotes.