Essentiality of mmpL3 and impact of its silencing on Mycobacterium tuberculosis gene expression.
Essentiality of mmpL3 and impact of its silencing on Mycobacterium tuberculosis gene expression.
复制标题
DOI：
10.1038/srep43495
复制
发表时间：
2017-02-27
影响因子：
4.6
通讯作者：
Manganelli R
中科院分区：
文献类型：
--
作者：
Degiacomi G;Benjak A;Madacki J;Boldrin F;Provvedi R;Palù G;Kordulakova J;Cole ST;Manganelli R
MmpL 3是结核分枝杆菌的内膜转运蛋白，负责输出海藻糖单霉菌酸酯、分枝杆菌外膜组分海藻糖二霉菌酸酯（TDM）的前体以及与阿拉伯半乳聚糖结合的霉菌酸。MmpL 3是结核病治疗的新靶点。在本文中，我们描述了一个mmpL 3敲低菌株的M.结核mmpL 3的下调导致细菌分裂停止和快速细胞死亡，随后是TDM前体的积累。MmpL 3也被证明是在单核细胞衍生的人巨噬细胞的生长所必需的。使用RNA-seq，我们还发现MmpL 3缺失导致47个基因上调和23个基因下调（至少3倍变化，错误发现率≤1%）。几个相关的基因的保护和金属稳态的诱导，而几个相关的能量生产和分枝菌酸生物合成的基因被抑制，这表明无法合成一个正确的外膜导致细胞渗透性和代谢下调的变化。
MmpL3 is an inner membrane transporter of Mycobacterium tuberculosis responsible for the export of trehalose momomycolate, a precursor of the mycobacterial outer membrane component trehalose dimycolate (TDM), as well as mycolic acids bound to arabinogalactan. MmpL3 represents an emerging target for tuberculosis therapy. In this paper, we describe the construction and characterization of an mmpL3 knockdown strain of M. tuberculosis. Downregulation of mmpL3 led to a stop in bacterial division and rapid cell death, preceded by the accumulation of TDM precursors. MmpL3 was also shown to be essential for growth in monocyte-derived human macrophages. Using RNA-seq we also found that MmpL3 depletion caused up-regulation of 47 genes and down-regulation of 23 genes (at least 3-fold change and false discovery rate ≤1%). Several genes related to osmoprotection and metal homeostasis were induced, while several genes related to energy production and mycolic acids biosynthesis were repressed suggesting that inability to synthesize a correct outer membrane leads to changes in cellular permeability and a metabolic downshift.