Unique repression domains of Pumilio utilize deadenylation and decapping factors to accelerate destruction of target mRNAs
Unique repression domains of Pumilio utilize deadenylation and decapping factors to accelerate destruction of target mRNAs
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DOI：
10.1093/nar/gkz1187
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发表时间：
2020-02-28
影响因子：
14.9
通讯作者：
Goldstrohm, Aaron C.
中科院分区：
文献类型：
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作者：
Arvola, Rene M.;Chang, Chung-Te;Goldstrohm, Aaron C.
Pumilio是一种RNA结合蛋白，其抑制mRNA网络以控制果蝇中的胚胎发生、干细胞命运、生育力和神经功能。我们试图确定Pumilio介导的抑制机制，并发现它加速了靶mRNA的降解，这是由三个N末端抑制结构域（RD）介导的，这是Pumilio直系同源物所特有的。我们发现，抑制活动的Pumilio的RD依赖于特定的亚基的Ccr 4-不（CNOT）deadenylase复合物。消耗Pop 2，Not 1，Not 2，或Not 3亚基，Pumilio RD介导的蛋白质表达和mRNA衰减的抑制，而消耗其他CNOT组件几乎没有或没有影响。此外，Pop 2去腺苷酶的催化活性对于Pumilio RD活性是重要的。此外，我们表明，Pumilio的RD直接结合到CNOT复合物。我们还报告说，decapping酶，Dcp 2，参与镇压的N末端的Pumilio。这些结果支持Pumilio利用CNOT去腺苷酶和去帽复合物加速靶mRNA破坏的模型。由于N-末端RD在哺乳动物Pumilio直系同源物中是保守的，因此这项工作的结果广泛地增强了我们对Pumilio功能和在包括癌症、神经变性和癫痫在内的疾病中的作用的理解。
Pumilio is an RNA-binding protein that represses a network of mRNAs to control embryogenesis, stem cell fate, fertility and neurological functions in Drosophila. We sought to identify the mechanism of Pumilio-mediated repression and find that it accelerates degradation of target mRNAs, mediated by three N-terminal Repression Domains (RDs), which are unique to Pumilio orthologs. We show that the repressive activities of the Pumilio RDs depend on specific subunits of the Ccr4-Not (CNOT) deadenylase complex. Depletion of Pop2, Not1, Not2, or Not3 subunits alleviates Pumilio RD-mediated repression of protein expression and mRNA decay, whereas depletion of other CNOT components had little or no effect. Moreover, the catalytic activity of Pop2 deadenylase is important for Pumilio RD activity. Further, we show that the Pumilio RDs directly bind to the CNOT complex. We also report that the decapping enzyme, Dcp2, participates in repression by the Nterminus of Pumilio. These results support a model wherein Pumilio utilizes CNOT deadenylase and decapping complexes to accelerate destruction of target mRNAs. Because the N-terminal RDs are conserved in mammalian Pumilio orthologs, the results of this work broadly enhance our understanding of Pumilio function and roles in diseases including cancer, neurodegeneration and epilepsy.