Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892.
Microbiol Spectr. 2018 Jul;6(4). doi: 10.1128/microbiolspec.RWR-0027-2018.
The study of bacteriophages (phages) and prophages has provided key insights into almost every cellular process as well as led to the discovery of unexpected new mechanisms and the development of valuable tools. This is exemplified for RNA-based regulation. For instance, the characterization and exploitation of the antiphage CRISPR (clustered regularly interspaced short palindromic repeat) systems is revolutionizing molecular biology. Phage-encoded proteins such as the RNA-binding MS2 protein, which is broadly used to isolate tagged RNAs, also have been developed as valuable tools. Hfq, the RNA chaperone protein central to the function of many base-pairing small RNAs (sRNAs), was first characterized as a bacterial host factor required for Qβ phage replication. The ongoing studies of RNAs are continuing to reveal regulatory connections between infecting phages, prophages, and bacteria and to provide novel insights. There are bacterial and prophage sRNAs that regulate prophage genes, which impact bacterial virulence as well as bacterial cell killing. Conversely, phage- and prophage-encoded sRNAs modulate the expression of bacterial genes modifying metabolism. An interesting subcategory of the prophage-encoded sRNAs are sponge RNAs that inhibit the activities of bacterial-encoded sRNAs. Phages also affect posttranscriptional regulation in bacteria through proteins that inhibit or alter the activities of key bacterial proteins involved in posttranscriptional regulation. However, what is most exciting about phage and prophage research, given the millions of phage-encoded genes that have not yet been characterized, is the vast potential for discovering new RNA regulators and novel mechanisms and for gaining insight into the evolution of regulatory RNAs.
噬菌体（phages）和原噬菌体的研究为几乎所有细胞过程提供了关键的见解，并导致了新的意外机制和有价值工具的发现。这在基于 RNA 的调控方面表现得尤为明显。例如，抗噬菌体 CRISPR（成簇的、规律间隔的短回文重复）系统的特征描述和利用正在彻底改变分子生物学。噬菌体编码的蛋白质，如广泛用于分离标记 RNA 的 RNA 结合蛋白 MS2 蛋白，也已被开发为有价值的工具。Hfq 是许多碱基配对小 RNA（sRNA）功能的核心 RNA 伴侣蛋白，最初被描述为 Qβ噬菌体复制所需的细菌宿主因子。对 RNA 的持续研究继续揭示感染噬菌体、原噬菌体和细菌之间的调控联系，并提供新的见解。有细菌和原噬菌体 sRNA 调节原噬菌体基因，这会影响细菌的毒力以及细菌细胞的杀伤。相反，噬菌体和原噬菌体编码的 sRNA 调节细菌基因的表达，从而改变代谢。原噬菌体编码的 sRNA 的一个有趣亚类是海绵 RNA，它可以抑制细菌编码的 sRNA 的活性。噬菌体还通过抑制或改变参与转录后调控的关键细菌蛋白的活性的蛋白质，影响细菌的转录后调控。然而，鉴于尚未鉴定的数以百万计的噬菌体编码基因，噬菌体和原噬菌体研究最令人兴奋的是发现新的 RNA 调节剂和新机制以及深入了解调节 RNA 的进化的巨大潜力。
