The outer membrane is an essential load-bearing element in Gram-negative bacteria.
The outer membrane is an essential load-bearing element in Gram-negative bacteria.
复制标题
DOI：
10.1038/s41586-018-0344-3
复制
发表时间：
2018-07
期刊：
影响因子：
64.8
通讯作者：
Huang KC
中科院分区：
文献类型：
--
作者：
Rojas ER;Billings G;Odermatt PD;Auer GK;Zhu L;Miguel A;Chang F;Weibel DB;Theriot JA;Huang KC
革兰氏阴性菌具有由质膜、肽聚糖细胞壁和外膜组成的复杂细胞包膜。包膜是一种选择性的化学屏障，它定义了细胞的形状，并允许细胞承受较大的机械负荷，如膨胀压力。人们普遍认为，共价交联的细胞壁赋予了包膜的力学性能。在这里，我们证明了大肠杆菌细胞的刚度和强度很大程度上是由于外膜。通过化学或遗传方式破坏外膜，会极大地增加细胞包膜在拉伸、弯曲和压痕力作用下的变形，并在机械扰动和l型增殖时诱导细胞裂解水平升高。脂多糖和蛋白质都对外膜刚度有贡献。这些发现推翻了“细胞壁是革兰氏阴性菌中主要的机械成分”的主流教条，相反，表明外膜可能比细胞壁更坚硬，并且机械负荷通常在这些结构之间平衡。
Gram-negative bacteria possess a complex cell envelope consisting of a plasma membrane, a peptidoglycan cell wall, and an outer membrane. The envelope is a selective chemical barrier that defines cell shape and allows the cell to sustain large mechanical loads such as turgor pressure. It is widely believed that the covalently cross-linked cell wall grants the envelope its mechanical properties. Here, we demonstrate that the stiffness and strength of Escherichia coli cells are largely due to the outer membrane. Compromising the outer membrane, chemically or genetically, greatly increased deformation of the cell envelope in response to stretching, bending, and indentation forces, and induced elevated levels of cell lysis upon mechanical perturbation and L-form proliferation. Both lipopolysaccharides and proteins contributed to outer membrane stiffness. These findings overturn the prevailing dogma that the cell wall is the dominant mechanical element within Gram-negative bacteria, instead demonstrating that the outer membrane can be more stiff than the cell wall and that mechanical loads are often balanced between these structures.
登录
查看更多内容
影响因子：
3.4
作者：
Cayley, DS;Guttman, HJ;Record, MT Jr
通讯作者：
Record, MT Jr
影响因子：
1.6
作者：
HUTTER, JL;BECHHOEFER, J
通讯作者：
BECHHOEFER, J
DOI：
10.1073/pnas.1317497111
发表时间：
2014-04-22
影响因子：
11.1
作者：
Amir, Ariel;Babaeipour, Farinaz;Jun, Suckjoon
通讯作者：
Jun, Suckjoon
影响因子：
16
作者：
Yao, Zhizhong;Kahne, Daniel;Kishony, Roy
通讯作者：
Kishony, Roy
影响因子：
64.5
作者：
Ruiz, N;Falcone, B;Silhavy, TJ
通讯作者：
Silhavy, TJ