Characterization of the ptr5^+ gene involved in nuclear mRNA export in fission yeast
Characterization of the ptr5^+ gene involved in nuclear mRNA export in fission yeast
复制标题
裂殖酵母中参与核 mRNA 输出的 ptr5^ 基因的表征
DOI：
10.1016/j.bbrc.2011.12.128
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发表时间：
2012
影响因子：
3.1
通讯作者：
Tokio Tani
中科院分区：
文献类型：
--
作者：
Nobuyoshi Watanabe;Terumasa Ikeda;Fumitaka Mizuki;Tokio Tani
为了分析mRNA从细胞核向细胞质输出的机制，我们分离了11个突变体ptr [poly(A)+RNA转运]1 ~ 11，它们在非允许温度下在核中积累poly(A)+RNA。其中，ptr5-1突变体在转移到非允许温度后，在核周围显示点状或环状聚积的聚(a)+RNA。我们克隆了ptr5+基因，发现它编码核孔复合体（NPC）的一个组成部分，核孔蛋白85 （Nup85）。ptr5-1突变体在蛋白质转运方面没有缺陷，表明Ptr5p/Nup85p特异性参与了pombe的核mRNA输出。我们发现Seh1p（一种与Nup85p相互作用的核孔蛋白）、Mlo3p（一种mRNA结合蛋白）和Sac3p （TREX-2复合体的一个组成部分，参与细胞核mRNA输出与转录的偶联）是ptr5-1突变的多拷贝抑制因子。此外，我们发现ptr5-1突变与mRNA输出因子Rae1p突变具有综合致死性，双突变加剧了细胞核mRNA输出缺陷，表明Ptr5p/Nup85p通过Rae1p参与细胞核mRNA输出。有趣的是，ptr5-1突变还显示出与几个prp pre-mRNA剪接突变的合成效应，这表明NPCs与酵母细胞核中的剪接装置之间存在功能联系。
To analyze the mechanisms of mRNA export from the nucleus to the cytoplasm, we have isolated eleven mutants, ptr [poly(A)+RNA transport] 1 to 11, which accumulate poly(A)+RNA in the nucleus at a nonpermissive temperature in Schizosaccharomyces pombe. Of those, the ptr5–1 mutant shows dots- or a ring-like accumulation of poly(A)+RNA at the nuclear periphery after shifting to the nonpermissive temperature. We cloned the ptr5+gene and found that it encodes a component of the nuclear pore complex (NPC), nucleoporin 85 (Nup85). The ptr5–1 mutant shows no defects in protein transport, suggesting the specific involvement of Ptr5p/Nup85p in nuclear mRNA export in S. pombe. We identified Seh1p, a nucleoporin interacting with Nup85p, an mRNA-binding protein Mlo3p, and Sac3p, a component of the TREX-2 complex involved in coupling of nuclear mRNA export with transcription, as multi-copy suppressors for the ptr5–1 mutation. In addition, we found that the ptr5–1 mutation is synthetically lethal with a mutation of the mRNA export factor Rae1p, and that the double mutant exaggerates defective nuclear mRNA export, suggesting that Ptr5p/Nup85p is involved in nuclear mRNA export through Rae1p. Interestingly, the ptr5–1 mutation also showed synthetic effects with several prp pre-mRNA splicing mutations, suggesting a functional linkage between the NPCs and the splicing apparatus in the yeast nucleus.