Nanoclusters of GPI-Anchored Proteins Are Formed by Cortical Actin-Driven Activity
Nanoclusters of GPI-Anchored Proteins Are Formed by Cortical Actin-Driven Activity
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DOI：
10.1016/j.cell.2008.11.032
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发表时间：
2008-12-12
期刊：
影响因子：
64.5
通讯作者：
Mayor, Satyajit
中科院分区：
文献类型：
--
作者：
Goswami, Debanjan;Gowrishankar, Kripa;Mayor, Satyajit
几种细胞表面脂质束缚蛋白质表现出浓度无关的，胆固醇敏感的纳米级簇和单体的组织。为了了解这些集群的形成机制，我们调查的空间分布和稳态动力学的荧光标记的GPI锚定的蛋白质纳米团簇使用高空间和时间分辨率FRET显微镜。这些研究揭示了纳米团簇的非随机空间分布，集中在光学可分辨域。监测荧光强度和各向异性的恢复的动态，我们发现，纳米簇是不动的，和纳米簇和单体之间的相互转换的动态，在一定的温度范围内，是空间异质性和非Arrhenius的，与急剧的交叉相吻合的皮质肌动蛋白的活性减少。胆固醇耗尽扰乱皮质肌动蛋白和纳米团簇的空间尺度和相互转换动力学。皮质肌动蛋白活性的直接扰动也会影响纳米簇的构建、动力学和空间组织。这些结果表明，皮层肌动蛋白活性调节的细胞表面分子的络合的一个独特的机制。
Several cell-surface lipid-tethered proteins exhibit a concentration-independent, cholesterol-sensitive organization of nanoscale clusters and monomers. To understand the mechanism of formation of these clusters, we investigate the spatial distribution and steady-state dynamics of fluorescently tagged GPI-anchored protein nanoclusters using high-spatial and temporal resolution FRET microscopy. These studies reveal a nonrandom spatial distribution of nanoclusters, concentrated in optically resolvable domains. Monitoring the dynamics of recovery of fluorescence intensity and anisotropy, we find that nanoclusters are immobile, and the dynamics of inter-conversion between nanoclusters and monomers, over a range of temperatures, is spatially heterogeneous and non-Arrhenius, with a sharp crossover coinciding with a reduction in the activity of cortical actin. Cholesterol depletion perturbs cortical actin and the spatial scale and interconversion dynamics of nanoclusters. Direct perturbations of cortical actin activity also affect the construction, dynamics, and spatial organization of nanoclusters. These results suggest a unique mechanism of complexation of cell-surface molecules regulated by cortical actin activity.