Independent mobility of proteins and lipids in the plasma membrane of Escherichia coli.
Independent mobility of proteins and lipids in the plasma membrane of Escherichia coli.
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DOI：
10.1111/mmi.12619
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发表时间：
2014-06
影响因子：
3.6
通讯作者：
Mullineaux CW
中科院分区：
文献类型：
--
作者：
Nenninger A;Mastroianni G;Robson A;Lenn T;Xue Q;Leake MC;Mullineaux CW
流动性对于许多生物膜功能是必不可少的。理解膜结构的基础仍然是经典的辛格-尼科尔森模型，其中蛋白质嵌入流体脂质双层中，并能够在脂质海洋中横向扩散。在这里，我们报告的脂质和蛋白质扩散的细菌大肠杆菌的活细胞的质膜，使用荧光恢复后光漂白（FRAP）和全内反射荧光（TIRF）显微镜测量横向扩散系数。通过可视化人工荧光脂质和简单模型膜蛋白来探测膜内的脂质和蛋白质迁移率，所述简单模型膜蛋白由在细胞质侧具有绿色荧光蛋白（GFP）标签的单个跨膜α-螺旋组成。的脂质双层的有效粘度是强烈的温度依赖性，如所示的脂质扩散系数的变化。令人惊讶的是，模型蛋白的流动性是不受影响的散装脂质的有效粘度的变化，和TIRF显微镜表明，它在隔离，移动的域集群。我们认为，这种分离深刻地影响了蛋白质在膜中的物理行为，对细菌膜功能和细菌生理学具有强烈的影响。
Fluidity is essential for many biological membrane functions. The basis for understanding membrane structure remains the classic Singer-Nicolson model, in which proteins are embedded within a fluid lipid bilayer and able to diffuse laterally within a sea of lipid. Here we report lipid and protein diffusion in the plasma membrane of live cells of the bacterium Escherichia coli, using Fluorescence Recovery after Photobleaching (FRAP) and Total Internal Reflection Fluorescence (TIRF) microscopy to measure lateral diffusion coefficients. Lipid and protein mobility within the membrane were probed by visualizing an artificial fluorescent lipid and a simple model membrane protein consisting of a single membrane-spanning alpha-helix with a Green Fluorescent Protein (GFP) tag on the cytoplasmic side. The effective viscosity of the lipid bilayer is strongly temperature-dependent, as indicated by changes in the lipid diffusion coefficient. Surprisingly, the mobility of the model protein was unaffected by changes in the effective viscosity of the bulk lipid, and TIRF microscopy indicates that it clusters in segregated, mobile domains. We suggest that this segregation profoundly influences the physical behaviour of the protein in the membrane, with strong implications for bacterial membrane function and bacterial physiology.
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影响因子：
3.5
作者：
Cormack, BP;Valdivia, RH;Falkow, S
通讯作者：
Falkow, S
DOI：
10.1073/pnas.0806338105
发表时间：
2008-10-07
影响因子：
11.1
作者：
Leake, Mark C.;Greene, Nicholas P.;Berks, Ben C.
通讯作者：
Berks, Ben C.
影响因子：
10.5
作者：
Lopez, Daniel;Kolter, Roberto
通讯作者：
Kolter, Roberto
影响因子：
64.8
作者：
Leake, Mark C.;Chandler, Jennifer H.;Armitage, Judith P.
通讯作者：
Armitage, Judith P.
DOI：
10.1073/pnas.120163297
发表时间：
2000-06-06
影响因子：
11.1
作者：
Datsenko, KA;Wanner, BL
通讯作者：
Wanner, BL