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科学家在细菌中发现新的免疫防线
作者:小柯机器人 发布时间:2020/11/7 15:28:51

以色列魏茨曼科学研究所Rotem Sorek课题组发现,细菌Retron参与抗噬菌体防御。2020年11月5日,《细胞》杂志在线发表了这项成果。

据介绍,Retron是由逆转录酶(RT)和非编码RNA(ncRNA)组成的细菌遗传元件。RT使用ncRNA作为模板,生成嵌合RNA/DNA分子,其中RNA和DNA组分共价连接。尽管Retron是在三十年前发现的,但其功能仍然未知。
 
研究人员发现,Retron可作为抗噬菌体防御系统。防御单元由三部分组成:RT、ncRNA和效应蛋白。研究人员检查了多个Retron系统,并显示它们通过顿挫感染来实现对广泛噬菌体的防御能力。
 
着眼于Retron Ec48,研究人员证明了它可以“保护” RecBCD(一种在细菌中具有核心抗噬菌体功能的复合物)。 噬菌体蛋白对RecBCD的抑制会激活Retron,从而导致顿挫感染和细胞死亡。因此,如果第一道防线已崩溃,Ec48 Retron会形成第二道防线。
 
附:英文原文

Title: Bacterial Retrons Function In Anti-Phage Defense

Author: Adi Millman, Aude Bernheim, Avigail Stokar-Avihail, Taya Fedorenko, Maya Voichek, Azita Leavitt, Yaara Oppenheimer-Shaanan, Rotem Sorek

Issue&Volume: 2020-11-05

Abstract: Retrons are bacterial genetic elements comprised of a reverse transcriptase (RT) anda non-coding RNA (ncRNA). The RT uses the ncRNA as template, generating a chimericRNA/DNA molecule in which the RNA and DNA components are covalently linked. Althoughretrons were discovered three decades ago, their function remained unknown. We reportthat retrons function as anti-phage defense systems. The defensive unit is composedof three components: the RT, the ncRNA, and an effector protein. We examined multipleretron systems and show that they confer defense against a broad range of phages viaabortive infection. Focusing on retron Ec48, we show evidence that it “guards” RecBCD,a complex with central anti-phage functions in bacteria. Inhibition of RecBCD by phageproteins activates the retron, leading to abortive infection and cell death. Thus,the Ec48 retron forms a second line of defense that is triggered if the first lines of defense have collapsed.

DOI: 10.1016/j.cell.2020.09.065

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)31306-4

期刊信息
Cell:《细胞》,创刊于1974年。隶属于细胞出版社,最新IF:36.216
官方网址:https://www.cell.com/