The Mla pathway in Acinetobacter baumannii has no demonstrable role in anterograde lipid transport.
The Mla pathway in Acinetobacter baumannii has no demonstrable role in anterograde lipid transport.
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DOI：
10.7554/elife.56571
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发表时间：
2020-09-03
期刊：
影响因子：
7.7
通讯作者：
Trent MS
中科院分区：
文献类型：
--
作者：
Powers MJ;Simpson BW;Trent MS
革兰氏阴性菌的不对称外膜（OM）是对环境的选择性渗透屏障。对OM脂质不对称性的扰动使细胞对抗生素敏感。因此，脂质不对称的机制是我们理解OM脂质稳态的基础。一种这样的机制，脂质不对称性维持（Mla）途径已被提出从OM的外小叶提取错误定位的甘油磷脂并将其返回内膜（IM）。在鲍曼不动杆菌中对该途径的研究支持Mla系统逆行（OM至IM）或顺行（IM至OM）方向性的相互冲突的模型。在这里，我们得出结论，A。鲍曼不动杆菌MLA突变体在顺行转运中没有表现出缺陷。此外，我们确定了一个等位基因的GTcobgE是合成病的Mla的情况下，提供了另一个细胞包膜稳态和严格的反应之间的联系。
The asymmetric outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier to the environment. Perturbations to OM lipid asymmetry sensitize the cell to antibiotics. As such, mechanisms involved in lipid asymmetry are fundamental to our understanding of OM lipid homeostasis. One such mechanism, the Maintenance of lipid asymmetry (Mla) pathway has been proposed to extract mislocalized glycerophospholipids from the outer leaflet of the OM and return them to the inner membrane (IM). Work on this pathway in Acinetobacter baumannii support conflicting models for the directionality of the Mla system being retrograde (OM to IM) or anterograde (IM to OM). Here, we show conclusively that A. baumannii mla mutants exhibit no defects in anterograde transport. Furthermore, we identify an allele of the GTPase obgE that is synthetically sick in the absence of Mla; providing another link between cell envelope homeostasis and stringent response.