Dissecting the actin cortex density and membrane-cortex distance in living cells by super-resolution microscopy
Dissecting the actin cortex density and membrane-cortex distance in living cells by super-resolution microscopy
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DOI：
10.1088/1361-6463/aa52a1
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发表时间：
2017-02-15
影响因子：
3.4
通讯作者：
Fritzsche, M.
中科院分区：
文献类型：
--
作者：
Clausen, M. P.;Colin-York, H.;Fritzsche, M.
细胞质膜和底层皮层肌动蛋白细胞骨架之间的纳米级间距深刻地调节细胞形态、力学和功能。测量这个距离一直是细胞生物学中的一个关键挑战。目前用于解剖纳米尺度间距的方法要么将其自身限制于使用固定样品的复杂勘测设计，要么依赖于衍射限制的荧光成像，其空间分辨率不足以量化纳米尺度上的距离。使用双色超分辨率STED（受激发射耗尽）显微镜，我们在这里克服了这一挑战，并准确地测量皮质肌动蛋白细胞骨架的密度分布和肌动蛋白皮质与活Jurkat T细胞膜之间的距离。我们发现了一个不对称的皮质肌动蛋白密度分布的平均宽度为230（+105/-125）nm。皮质和膜的最大密度峰之间测量的空间距离呈双峰分布，平均值分别为50 +/- 15 nm和120 +/- 40 nm。考虑到皮质的有限宽度，我们的研究结果表明，在某些区域的皮质肌动蛋白是更接近于10 nm的膜和最大的20 nm的其他。
Nanoscale spacing between the plasma membrane and the underlying cortical actin cytoskeleton profoundly modulates cellular morphology, mechanics, and function. Measuring this distance has been a key challenge in cell biology. Current methods for dissecting the nanoscale spacing either limit themselves to complex survey design using fixed samples or rely on diffraction-limited fluorescence imaging whose spatial resolution is insufficient to quantify distances on the nanoscale. Using dual-color super-resolution STED (stimulated-emission-depletion) microscopy, we here overcome this challenge and accurately measure the density distribution of the cortical actin cytoskeleton and the distance between the actin cortex and the membrane in live Jurkat T-cells. We found an asymmetric cortical actin density distribution with a mean width of 230 (+105/-125) nm. The spatial distances measured between the maximum density peaks of the cortex and the membrane were bi-modally distributed with mean values of 50 +/- 15 nm and 120 +/- 40 nm, respectively. Taken together with the finite width of the cortex, our results suggest that in some regions the cortical actin is closer than 10 nm to the membrane and a maximum of 20 nm in others.