PDF(Pubmed)
Abstract：
Viral genomes are most vulnerable to cellular defenses at the start of the infection. A family of jumbo phages related to phage ΦKZ, which infects Pseudomonas aeruginosa, assembles a protein-based phage nucleus to protect replicating phage DNA, but how it is protected prior to phage nucleus assembly is unclear. We find that host proteins related to membrane and lipid biology interact with injected phage protein, clustering in an early phage infection (EPI) vesicle. The injected virion RNA polymerase (vRNAP) executes early gene expression until phage genome separation from the vRNAP and the EPI vesicle, moving into the nascent proteinaceous phage nucleus. Enzymes involved in DNA replication and CRISPR/restriction immune nucleases are excluded by the EPI vesicle. We propose that the EPI vesicle is rapidly constructed with injected phage proteins, phage DNA, host lipids, and host membrane proteins to enable genome protection, early transcription, localized translation, and to ensure faithful genome transfer to the proteinaceous nucleus.
摘要：
病毒基因组在感染开始时最容易受到细胞防御的影响。与噬菌体ΦKZ相关的巨型噬菌体家族，感染铜绿假单胞菌，组装一个基于蛋白质的噬菌体核来保护复制的噬菌体DNA，但是在噬菌体核组装之前如何保护它还不清楚。我们发现与膜和脂质生物学相关的宿主蛋白与注射的噬菌体蛋白相互作用，聚集在早期噬菌体感染（EPI）囊泡中。注射的病毒体RNA聚合酶（vRNAP）执行早期基因表达，直到噬菌体基因组与vRNAP和EPI囊泡分离，进入新生的蛋白质噬菌体细胞核。EPI囊泡排除了参与DNA复制和CRISPR/限制性免疫核酸酶的酶。我们建议用注射的噬菌体蛋白快速构建EPI囊泡，噬菌体DNA,宿主脂质，和宿主膜蛋白来实现基因组保护，早期转录，本地化翻译,并确保可靠的基因组转移到蛋白质细胞核。
