RNA-binding protein Mub1 and the nuclear RNA exosome act to fine-tune environmental stress response.
RNA-binding protein Mub1 and the nuclear RNA exosome act to fine-tune environmental stress response.
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DOI：
10.26508/lsa.202101111
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发表时间：
2022-03
影响因子：
4.4
通讯作者：
Kilchert C
中科院分区：
文献类型：
--
作者：
Birot A;Kus K;Priest E;Al Alwash A;Castello A;Mohammed S;Vasiljeva L;Kilchert C
比较RNA相互作用组捕获识别裂变酵母中RNA代谢的潜在调节剂，并揭示了应激反应基因表达网络的RNA外泌体依赖性缓冲。核RNA外泌体在控制多种蛋白质编码和非编码RNA的水平中起关键作用。外泌体向特定RNA底物的募集是由RNA结合辅因子介导的。辅因子与外泌体之间的瞬时相互作用以及RNA底物的快速衰减使得外泌体辅因子的鉴定具有挑战性。在这里，我们使用比较聚（A）+ RNA相互作用组捕获在裂变酵母表达三种不同的外泌体突变体，以确定蛋白质与聚（A）+ RNA相互作用的外泌体依赖性的方式。我们的分析确定了多种RNA结合蛋白，其与RNA的结合在外泌体突变体中发生了改变，包括锌指蛋白Mub1。Mub1是维持外泌体RNA底物（包括编码应激反应蛋白的mRNA）亚组水平所必需的。锌指结构域的去除导致在非应激条件下RNA抑制的丧失，响应于应激的热休克基因的表达改变，以及在升高的温度下生长减少。这些发现突出了外泌体依赖性mRNA降解在缓冲基因表达网络以介导细胞对应激的适应中的重要性。
Comparative RNA interactome capture identifies potential regulators of RNA metabolism in fission yeast and reveals RNA exosome–dependent buffering of stress-responsive gene expression networks. The nuclear RNA exosome plays a key role in controlling the levels of multiple protein-coding and non-coding RNAs. Recruitment of the exosome to specific RNA substrates is mediated by RNA-binding co-factors. The transient interaction between co-factors and the exosome as well as the rapid decay of RNA substrates make identification of exosome co-factors challenging. Here, we use comparative poly(A)+ RNA interactome capture in fission yeast expressing three different mutants of the exosome to identify proteins that interact with poly(A)+ RNA in an exosome-dependent manner. Our analyses identify multiple RNA-binding proteins whose association with RNA is altered in exosome mutants, including the zinc-finger protein Mub1. Mub1 is required to maintain the levels of a subset of exosome RNA substrates including mRNAs encoding for stress-responsive proteins. Removal of the zinc-finger domain leads to loss of RNA suppression under non-stressed conditions, altered expression of heat shock genes in response to stress, and reduced growth at elevated temperature. These findings highlight the importance of exosome-dependent mRNA degradation in buffering gene expression networks to mediate cellular adaptation to stress.