Control of Listeria superoxide dismutase by phosphorylation
Control of Listeria superoxide dismutase by phosphorylation
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DOI：
10.1074/jbc.m606249200
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发表时间：
2006-10-20
影响因子：
4.8
通讯作者：
Dussurget, Olivier
中科院分区：
文献类型：
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作者：
Archambaud, Cristel;Nahori, Marie-Anne;Dussurget, Olivier
超氧化物歧化酶 (SOD) 是保护生物体免受其活跃代谢过程中产生的超氧化物和活性氧 (ROS) 侵害的酶。 ROS 是吞噬细胞杀菌活性的主要介质。在这里，我们发现细胞质单增李斯特菌 MnSOD 在丝氨酸和苏氨酸残基上被磷酸化，并且当细菌到达稳定期时活性较低。我们还提供证据表明，最活跃的非磷酸化形式的 MnSOD 可以通过培养物上清液和感染细胞中的 SecA2 途径分泌，并在感染细胞中磷酸化。 Delta sod 缺失突变体在巨噬细胞内的存活受到损害，并且在小鼠中显着减弱。总之，我们的结果表明，抵抗 ROS 的能力是单核细胞增生李斯特菌毒力的重要组成部分。这是细菌 SOD 翻译后受磷酸化控制的第一个例子，表明可能有一种新的宿主先天机制来抵消毒力因子。
Superoxide dismutases (SODs) are enzymes that protect organisms against superoxides and reactive oxygen species (ROS) produced during their active metabolism. ROS are major mediators of phagocytes microbicidal activity. Here we show that the cytoplasmic Listeria monocytogenes MnSOD is phosphorylated on serine and threonine residues and less active when bacteria reach the stationary phase. We also provide evidence that the most active nonphosphorylated form of MnSOD can be secreted via the SecA2 pathway in culture supernatants and in infected cells, where it becomes phosphorylated. A Delta sod deletion mutant is impaired in survival within macrophages and is dramatically attenuated in mice. Together, our results demonstrate that the capacity to counteract ROS is an essential component of L. monocytogenes virulence. This is the first example of a bacterial SOD post-translationally controlled by phosphorylation, suggesting a possible new host innate mechanism to counteract a virulence factor.