Meiotic gene silencing complex MTREC/NURS recruits the nuclear exosome to YTH-RNA-binding protein Mmi1
Meiotic gene silencing complex MTREC/NURS recruits the nuclear exosome to YTH-RNA-binding protein Mmi1
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DOI：
10.1371/journal.pgen.1008598
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发表时间：
2020-02
期刊：
影响因子：
4.5
通讯作者：
Yuichi Shichino;Yoko Otsubo;Masayuki Yamamoto;A. Yamashita
中科院分区：
文献类型：
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作者：
Yuichi Shichino;Yoko Otsubo;Masayuki Yamamoto;A. Yamashita
转录物降解过程中靶点的准确识别对基因表达调控至关重要。在裂殖酵母裂殖酵母中，许多减数分裂转录物被YTH家族RNA结合蛋白Mmi 1识别，并在有丝分裂生长期间被核外泌体选择性降解。mmi 1在有丝分裂生长的细胞中形成核灶，并且核外泌体共定位于这样的灶。然而，Mmi 1和核外泌体是如何连接的仍然难以捉摸。在这里，我们表明，一个复杂的称为MTREC（Mtl 1-Red 1核心）或CRISPS（核RNA沉默），由一个锌指蛋白，Red 1，和RNA解旋酶，Mtl 1，是所需的招聘核外泌体Mmi 1灶。Mmi 1和核外泌体之间的物理相互作用取决于Red 1。此外，涉及Mmi 1和Rrp 6的嵌合蛋白（其是外泌体的核特异性组分）抑制red 1 Δ细胞和mtl 1突变细胞中减数分裂转录物的异位表达表型。这些数据表明，在减数分裂的转录消除MTREC/MATRIS的主要功能是连接Mmi 1的核外泌体物理。
Accurate target recognition in transcript degradation is crucial for regulation of gene expression. In the fission yeast Schizosaccharomyces pombe, a number of meiotic transcripts are recognized by a YTH-family RNA-binding protein, Mmi1, and selectively degraded by the nuclear exosome during mitotic growth. Mmi1 forms nuclear foci in mitotically growing cells, and the nuclear exosome colocalizes to such foci. However, it remains elusive how Mmi1 and the nuclear exosome are connected. Here, we show that a complex called MTREC (Mtl1-Red1 core) or NURS (nuclear RNA silencing) that consists of a zinc-finger protein, Red1, and an RNA helicase, Mtl1, is required for the recruitment of the nuclear exosome to Mmi1 foci. Physical interaction between Mmi1 and the nuclear exosome depends on Red1. Furthermore, a chimeric protein involving Mmi1 and Rrp6, which is a nuclear-specific component of the exosome, suppresses the ectopic expression phenotype of meiotic transcripts in red1Δ cells and mtl1 mutant cells. These data indicate that the primary function of MTREC/NURS in meiotic transcript elimination is to link Mmi1 to the nuclear exosome physically.