Aminopeptidase T of M29 Family Acts as A Novel Intracellular Virulence Factor for Listeria monocytogenes Infection.
Aminopeptidase T of M29 Family Acts as A Novel Intracellular Virulence Factor for Listeria monocytogenes Infection.
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M29 家族的氨肽酶 T 作为单核细胞增生李斯特菌感染的新型细胞内毒力因子
DOI：
10.1038/srep17370
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发表时间：
2015-11-27
影响因子：
4.6
通讯作者：
Song H
中科院分区：
文献类型：
--
作者：
Cheng C;Wang X;Dong Z;Shao C;Yang Y;Fang W;Fang C;Wang H;Yang M;Jiang L;Zhou X;Song H
食源性病原体单核细胞增生李斯特菌利用包括金属蛋白酶在内的许多毒力决定因子来感染宿主。本文首次从L.单核细胞增多症具有催化氨基酸从肽底物裂解的典型特征，优选精氨酸。纯化的重组Lmo 1603被Fe 3+、Zn 2+和Mn 2+激活，但被Co 2+强烈激活，表明Lmo 1603是钴依赖性氨肽酶。在Glu 216、Glu 281、His 308、Tyr 315、His327和Asp329中的任一个处的单突变完全消除Lmo 1603的酶活性。更重要的是，我们发现Lmo 1603主要参与李斯特菌感染，但在丰富的实验室培养基和基本限定培养基中不需要生长。在小鼠感染模型中，Lmo 1603的破坏导致李斯特菌毒力几乎完全衰减。此外，我们证明Lmo1603主要定位于细菌胞质溶胶中，并且是人类上皮细胞和小鼠巨噬细胞内的侵袭和存活所必需的。结论：Lmo 1603编码M29家族的一种功能性氨肽酶T，它是一种新的细胞内毒力因子，在L.单核细胞增多症感染的小鼠模型。
The foodborne pathogen Listeria monocytogenes employs a number of virulence determinants including metalloproteases to infect hosts. Here for the first time, we identified an M29 family aminopeptidase T (encoded by lmo1603) from L. monocytogenes that possesses a typical feature to catalyze the cleavage of amino acids from peptide substrates, with a preference for arginine. The purified recombinant Lmo1603 was activated by Fe3+, Zn2+ and Mn2+, but strongly stimulated by Co2+, indicating that Lmo1603 is a cobalt-dependent aminopeptidase. Single mutation at any of the Glu216, Glu281, His308, Tyr315, His327, and Asp329 completely abolished the enzymatic activity of Lmo1603. More importantly, we showed that Lmo1603 was mainly involved in Listeria infection, but not required for growth in rich laboratory medium and minimal defined medium. Disruption of Lmo1603 resulted in almost complete attenuation of Listeria virulence in a mouse infection model. In addition, we demonstrated that Lmo1603 was mainly localized in the bacterial cytosol and required for invasion and survival inside human epithelial cells and murine macrophages. We conclude that Lmo1603 encodes a functional aminopeptidase T of M29 family, which acts as a novel intracellular virulence factor essential in the successful establishment of L. monocytogenes infections in a mouse model.