RNA-binding proteins (RBPs) perform key cellular activities by controlling the function of bound RNAs. The widely held assumption that RBPs are strictly intracellular has been challenged by the discovery of secreted RBPs. However, extracellular RBPs have been described in eukaryotes, while secreted bacterial RBPs have not been reported. Here, we show that the bacterial pathogen Listeria monocytogenes secretes a small RBP that we named Zea. We show that Zea binds a subset of L. monocytogenes RNAs, causing their accumulation in the extracellular medium. Furthermore, during L. monocytogenes infection, Zea binds RIG-I, the non-self-RNA innate immunity sensor, potentiating interferon-β production. Mouse infection studies reveal that Zea affects L. monocytogenes virulence. Together, our results unveil that bacterial RNAs can be present extracellularly in association with RBPs, acting as "social RNAs" to trigger a host response during infection.

中文翻译：

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细菌病原体分泌的 RNA 结合蛋白调节 RIG-I 信号。

RNA 结合蛋白 (RBP) 通过控制结合 RNA 的功能来执行关键的细胞活动。RBP 是严格细胞内的这一广泛持有的假设已受到分泌型 RBP 的发现的挑战。然而，已经在真核生物中描述了细胞外 RBP，而尚未报道分泌的细菌 RBP。在这里，我们展示了细菌病原体单核细胞增生李斯特菌分泌一种我们命名为 Zea 的小 RBP。我们展示了玉米与单核细胞增生李斯特菌 RNA 的一个子集结合，导致它们在细胞外培养基中积累。此外，在单核细胞增生李斯特菌感染期间，玉米与 RIG-I（非自身 RNA 先天免疫传感器）结合，增强了干扰素-β 的产生。小鼠感染研究表明，玉米会影响单核细胞增生李斯特氏菌的毒力。一起，