Characterization of extracellular membrane vesicles of an Antarctic bacterium, Shewanella livingstonensis Ac10, and their enhanced production by alteration of phospholipid composition
Characterization of extracellular membrane vesicles of an Antarctic bacterium, Shewanella livingstonensis Ac10, and their enhanced production by alteration of phospholipid composition
复制标题
南极细菌 Shewanella Livingstonensis Ac10 的细胞外膜囊泡的表征，以及通过改变磷脂组成来增强其产量
作者：
Fumiaki Yokoyama;J. Kawamoto;T. Imai;T. Kurihara
冷适应细菌Shewanella livingstonensis Ac10产生二十碳五烯酸(EPA)作为其膜磷脂的组成部分，是研究EPA功能的模型，也是低温下异源生产不耐热蛋白的宿主。在这项研究中，我们对该细菌的胞外膜小泡(EMVS)进行了表征，以探讨EPA在EMVS的生物发生中的作用，并为EMVS在胞外蛋白生产中的应用奠定基础。我们发现该菌株能从细胞表面产生EMVS。低温电子显微镜观察表明，大多数EMVS为单双层结构，平均直径为110 nm，但也观察到具有双双层膜的EMVS和其他不同的结构。定量分析表明，EPA磷脂的消耗使EMV产量显著增加(3-5倍)。EPA的缺乏也改变了EMVS的蛋白质组成。特别是，在EPA耗尽后，EMVS中冷诱导外膜蛋白OmpC176的掺入显著增加。这些结果为构建基于EMV的低温蛋白质生产系统提供了依据，并表明EPA参与了EMV生物发生的调控。
A cold-adapted bacterium, Shewanella livingstonensis Ac10, which produces eicosapentaenoic acid (EPA) as a component of its membrane phospholipids, is useful as a model to study the function of EPA and as a host for heterologous production of thermolabile proteins at low temperatures. In this study, we characterized extracellular membrane vesicles (EMVs) of this bacterium to examine the involvement of EPA in the biogenesis of EMVs and for the future application of EMVs to extracellular protein production. We found that this strain produced EMVs from the cell surface. Cryo-electron microscopic observation showed that the majority of the EMVs had a single-bilayer structure with an average diameter of 110 nm, though EMVs with double-bilayer membranes and other diverse structures were also observed. Quantitative analysis demonstrated that the EMV production was significantly increased (3–5 fold) by the depletion of EPA-containing phospholipids. The lack of EPA also altered the protein composition of EMVs. In particular, incorporation of one of the cold-inducible outer membrane proteins, OmpC176, was significantly increased in EMVs after the depletion of EPA. These results provide a basis for the construction of an EMV-based, low-temperature protein production system and show the involvement of EPA in the regulation of EMV biogenesis.
影响因子：
10.5
作者：
Kulp A;Kuehn MJ
通讯作者：
Kuehn MJ