A phage nucleus-associated RNA-binding protein is required for jumbo phage infection.
A phage nucleus-associated RNA-binding protein is required for jumbo phage infection.
复制标题
巨噬菌体感染需要噬菌体核相关 RNA 结合蛋白。
DOI：
10.1101/2023.09.22.559000
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Ghassemia
中科院分区：
文献类型：
--
作者：
Enustun,Eray;Armbruster,EmilyG;Lee,Jina;Zhang,Sitao;Yee,BrianA;Gu,Yajie;Deep,Amar;Naritomi,JackT;Liang,Qishan;Aigner,Stefan;Adler,BenjaminA;Cress,BradyF;Doudna,JenniferA;Chaikeeratisak,Vorrapon;Cleveland,DonW;Ghassemia
Chimalliviridae家族的大基因组噬菌体（巨型噬菌体）组装一个由蛋白质外壳包围的核样隔室，以保护复制的噬菌体基因组免受宿主编码的限制性内切酶和靶向dna的CRISPR-Cas核酸酶的侵害。虽然核壳对宿主核酸酶提供了广泛的保护，但它需要将mRNA运输出类核室以供宿主核糖体翻译，并将特定蛋白质运输到类核室以支持DNA复制和mRNA转录。在这里，我们鉴定了一种保守的噬菌体核壳相关蛋白，我们称之为Chimallin C (ChmC)，它采用核酸结合折叠，在体外以高亲和力结合RNA，并在感染细胞中结合噬菌体mrna。ChmC与RNAin在体外形成相分离凝聚物。利用mrna靶向dCas13d靶向敲低ChmC导致噬菌体编码mrna在噬菌体细胞核中积累，减少噬菌体蛋白的产生，并影响病毒粒子的组装。综上所述，我们的数据表明，保守的ChmC蛋白在病毒生命周期中起着至关重要的作用，可能通过促进噬菌体mRNA通过核壳转运来促进蛋白质的产生和病毒粒子的发育。
Large-genome bacteriophages (jumbo phages) of the proposed family Chimalliviridae assemble a nucleus-like compartment bounded by a protein shell that protects the replicating phage genome from host-encoded restriction enzymes and DNA-targeting CRISPR-Cas nucleases. While the nuclear shell provides broad protection against host nucleases, it necessitates transport of mRNA out of the nucleus-like compartment for translation by host ribosomes, and transport of specific proteins into the nucleus-like compartment to support DNA replication and mRNA transcription. Here, we identify a conserved phage nuclear shell-associated protein that we term Chimallin C (ChmC), which adopts a nucleic acid-binding fold, binds RNA with high affinityin vitro, and binds phage mRNAs in infected cells. ChmC also forms phase-separated condensates with RNAin vitro. Targeted knockdown of ChmC using mRNA-targeting dCas13d results in accumulation of phage-encoded mRNAs in the phage nucleus, reduces phage protein production, and compromises virion assembly. Taken together, our data show that the conserved ChmC protein plays crucial roles in the viral life cycle, potentially by facilitating phage mRNA translocation through the nuclear shell to promote protein production and virion development.