研究人员发现，细菌和古细菌中的抗病毒STAND（Avs）同源物可检测到标志性的病毒蛋白，并触发Avs四聚体化和激活不同的N端效应域，包括DNA内切酶，从而阻止感染。冷冻电镜显示，Avs传感器结构域识别保守的褶皱、活性位点残基和酶配体，使单一的Avs受体能够检测各种病毒。这些发现扩展了病原体特异性蛋白的模式识别范式，跨越了生命的所有三个领域。
据介绍，许多生物已经进化出专门的免疫模式识别受体，包括在植物、动物和真菌中无处不在的STAND超家族的核苷酸结合寡聚域样受体（NLR）。尽管NLR在真核生物免疫中的作用已得到确认，但原核生物是否使用类似的防御机制尚不清楚。
附：英文原文
Title: Prokaryotic innate immunity through pattern recognition of conserved viral proteins
Author: Linyi Alex Gao, Max E. Wilkinson, Jonathan Strecker, Kira S. Makarova, Rhiannon K. Macrae, Eugene V. Koonin, Feng Zhang
Issue&Volume: 2022-08-12
Abstract: Many organisms have evolved specialized immune pattern-recognition receptors, including nucleotide-binding oligomerization domain–like receptors (NLRs) of the STAND superfamily that are ubiquitous in plants, animals, and fungi. Although the roles of NLRs in eukaryotic immunity are well established, it is unknown whether prokaryotes use similar defense mechanisms. Here, we show that antiviral STAND (Avs) homologs in bacteria and archaea detect hallmark viral proteins, triggering Avs tetramerization and the activation of diverse N-terminal effector domains, including DNA endonucleases, to abrogate infection. Cryo–electron microscopy reveals that Avs sensor domains recognize conserved folds, active-site residues, and enzyme ligands, allowing a single Avs receptor to detect a wide variety of viruses. These findings extend the paradigm of pattern recognition of pathogen-specific proteins across all three domains of life.
DOI: abm4096
Source: https://www.science.org/doi/10.1126/science.abm4096