小柯机器人

美国普林斯顿大学Bonnie L. Bassler研究小组发现，小蛋白模块决定多糖发生过程中噬菌体的命运。该项研究成果于2023年7月26日在线发表在《自然》杂志上。

研究人员发现了控制噬菌体诱导的调控模块，这些模块独立于DNA损伤线索。这些模块在序列水平上几乎没有相似之处，但通过一个转录因子激活邻近编码小蛋白的基因的表达，从而共享一个调控逻辑。小蛋白使溶解的核心抑制因子失活，从而引起诱导。含有两种原噬菌体的多聚溶原体受到DNA损伤后会释放出混合噬菌体群。单细胞分析表明，这种混合是产生一种、另一种或两种噬菌体的离散细胞亚群的结果。

相比之下，通过与DNA损伤无关的模块进行诱导，细胞只产生对特定线索敏感的噬菌体。因此，在测试的多聚溶原体中，用于诱导溶解的刺激决定了噬菌体的产量。考虑到自然栖息地缺乏强效的DNA损伤剂，噬菌体编码的其他溶解感知途径很可能在噬菌体-宿主生物学和噬菌体间竞争中发挥重要作用。

据介绍，据预测，生物圈中的大多数细菌都是携带多种原噬菌体的多聚溶原体。在所研究的系统中，从溶原性到溶解的噬菌体诱导过程几乎都是由DNA破坏因子驱动的。因此，如果共存的噬菌体对相同的触发做出反应，它们如何竞争细胞资源尚不清楚。

附：英文原文

Title: Small protein modules dictate prophage fates during polylysogeny

Author: Silpe, Justin E., Duddy, Olivia P., Johnson, Grace E., Beggs, Grace A., Hussain, Fatima A., Forsberg, Kevin J., Bassler, Bonnie L.

Issue&Volume: 2023-07-26

Abstract: Most bacteria in the biosphere are predicted to be polylysogens harbouring multiple prophages1,2,3,4,5. In studied systems, prophage induction from lysogeny to lysis is near-universally driven by DNA-damaging agents6. Thus, how co-residing prophages compete for cell resources if they respond to an identical trigger is unknown. Here we discover regulatory modules that control prophage induction independently of the DNA-damage cue. The modules bear little resemblance at the sequence level but share a regulatory logic by having a transcription factor that activates the expression of a neighbouring gene that encodes a small protein. The small protein inactivates the master repressor of lysis, which leads to induction. Polylysogens that harbour two prophages exposed to DNA damage release mixed populations of phages. Single-cell analyses reveal that this blend is a consequence of discrete subsets of cells producing one, the other or both phages. By contrast, induction through the DNA-damage-independent module results in cells producing only the phage sensitive to that specific cue. Thus, in the polylysogens tested, the stimulus used to induce lysis determines phage productivity. Considering the lack of potent DNA-damaging agents in natural habitats, additional phage-encoded sensory pathways to lysis likely have fundamental roles in phage–host biology and inter-prophage competition.

DOI: 10.1038/s41586-023-06376-y

Source: https://www.nature.com/articles/s41586-023-06376-y

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