LI1035, a putative effector secreted by Lawsonia intracellularis, targets the MAPK pathway and regulates actin organizationin yeast and mammalian cells
LI1035, a putative effector secreted by Lawsonia intracellularis, targets the MAPK pathway and regulates actin organizationin yeast and mammalian cells
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LI1035 是一种由胞内劳森菌分泌的推定效应子，以 MAPK 通路为目标，调节酵母和哺乳动物细胞中的肌动蛋白组织
DOI：
10.1016/j.vetmic.2019.06.009
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发表时间：
2019-08-01
影响因子：
3.3
通讯作者：
Dai, Yimin
中科院分区：
文献类型：
--
作者：
Yang, Lijuan;Lai, Fenju;Dai, Yimin
胞内Lawsonia胞内Lawsonia胞内革兰氏阴性杆菌是一种专性胞内革兰氏阴性菌，已被确定为多种动物（主要是猪）传染性增生性肠病（PE）的病原。胞内乳杆菌的基因组序列表明，该细菌具有III型分泌系统（T3SS），该系统可能在细胞入侵和逃避宿主先天免疫系统时提供辅助，并可能是诱导细胞增殖的机制之一。然而，胞内乳杆菌T3SS （T3Es）分泌的效应物尚未见报道。T3Es通常以保守的真核细胞过程为靶点，酵母是一个成熟且强大的模型系统，可以揭示它们的功能。通过筛选表达胞内L.胞内菌基因的酿酒酵母菌株，LI1035被认为是第一个抑制酵母生长的效应物。在14个丝裂原活化蛋白激酶（MAPK）酵母单倍体缺失菌株中，LI1035诱导的生长抑制在两个菌株中被恢复，这表明LI1035与酵母中MAPK通路的组分相互作用。磷酸化实验证实LI1035在酵母和哺乳动物细胞中抑制MAPK信号级联反应。肌动蛋白染色分析显示LI1035调节酵母和哺乳动物细胞中的肌动蛋白组织。综上所述，这些结果表明LI1035改变了宿主的MAPK通路活性并调节了肌动蛋白的组织。这些发现可能有助于了解胞内乳杆菌的发病机制，并支持将酵母作为异源系统在实验室中进行病原体特异性基因产物的功能分析。
Lawsonia intracellularis is an obligate intracellular Gram-negative bacterium that has been identified as the etiological agent of the contagious disease proliferative enteropathy (PE) in a wide range of animals, mainly pigs. The genome sequence of L. intracellularis indicates that this bacterium possess a type III secretion system (T3SS), which may assist the bacterium during cell invasion and host innate immune system evasion and could be a mechanism for inducing cellular proliferation. However, the effectors secreted by the T3SS (T3Es) of L. intracellularis have not been reported. T3Es often target conserved eukaryotic cellular processes, and yeast is an established and robust model system in which to reveal their function. By screening the growth inhibition of an ordered array of Saccharomyces cerevisiae strains expressing the hypothetical genes of L. intracellularis, LI1035 was identified as the first putative effector that inhibits yeast growth. The LI1035-induced growth inhibition was rescued in two of the 14 mitogen-activated protein kinase (MAPK) yeast haploid deletion strains, suggesting that LI1035 interacts with the components of the MAPK pathway in yeast. Phosphorylation assays confirmed that LI1035 inhibits MAPK signaling cascades in yeast and mammalian cells. Actin staining assays revealed that LI1035 regulates actin organization in yeast and mammalian cells. Taken together, these results indicate that LI1035 alters MAPK pathway activity and regulates actin organization in the host. These findings may contribute to the understanding the pathogenesis of L. intracellularis and support the use of yeast as a heterologous system for the functional analysis of pathogen-specific gene products in the laboratory.