Using S. cerevisiae as a Model System to Investigate V. cholerae VopX-Host Cell Protein Interactions and Phenotypes.
Using S. cerevisiae as a Model System to Investigate V. cholerae VopX-Host Cell Protein Interactions and Phenotypes.
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DOI：
10.3390/toxins7104099
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发表时间：
2015-10-14
期刊：
影响因子：
4.2
通讯作者：
Dziejman M
中科院分区：
文献类型：
--
作者：
Seward CH;Manzella A;Alam A;Butler JS;Dziejman M
大多数致病性、非O1/非O139群霍乱弧菌菌株在没有霍乱毒素的情况下会引起腹泻疾病。相反，许多人使用3型分泌系统(T3SS)介导的机制来破坏宿主细胞的动态平衡。我们鉴定了一种T3SS效应蛋白VopX，它在体外共培养过程中被转移到哺乳动物细胞中。在酿酒酵母模型系统中，我们发现VopX的表达导致了严重的生长缺陷，而RLM1的缺失部分抑制了RLM1的表达，RLM1编码细胞壁完整性地图激酶(CWI)调节通路的末端转录调节因子。酵母细胞在山梨醇存在下的生长也抑制了缺陷，支持了VopX在破坏细胞壁稳定方面的作用。VopX的表达激活了来自RLM1反应元件报告融合的β-半乳糖苷酶的表达，但在RLM1上游缺乏MAP激酶的细胞中未能做到这一点。结果提示，VopX通过Rlm1刺激CWI途径抑制细胞生长。RLM1是哺乳动物MEF2转录因子的同源基因，被认为可以调节细胞的分化、增殖和凋亡。这些集体发现表明，VopX通过激活MAP激酶级联，导致细胞转录程序发生变化，从而导致疾病。
Most pathogenic, non-O1/non-O139 serogroup Vibrio cholerae strains cause diarrheal disease in the absence of cholera toxin. Instead, many use Type 3 Secretion System (T3SS) mediated mechanisms to disrupt host cell homeostasis. We identified a T3SS effector protein, VopX, which is translocated into mammalian cells during in vitro co-culture. In a S. cerevisiae model system, we found that expression of VopX resulted in a severe growth defect that was partially suppressed by a deletion of RLM1, encoding the terminal transcriptional regulator of the Cell Wall Integrity MAP kinase (CWI) regulated pathway. Growth of yeast cells in the presence of sorbitol also suppressed the defect, supporting a role for VopX in destabilizing the cell wall. Expression of VopX activated expression of β-galactosidase from an RLM1-reponsive element reporter fusion, but failed to do so in cells lacking MAP kinases upstream of Rlm1. The results suggest that VopX inhibits cell growth by stimulating the CWI pathway through Rlm1. Rlm1 is an ortholog of mammalian MEF2 transcription factors that are proposed to regulate cell differentiation, proliferation, and apoptosis. The collective findings suggest that VopX contributes to disease by activating MAP kinase cascades that elicit changes in cellular transcriptional programs.