Nonmuscle myosin II is a critical regulator of clathrin-mediated endocytosis.
Nonmuscle myosin II is a critical regulator of clathrin-mediated endocytosis.
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DOI：
10.1111/tra.12152
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发表时间：
2014-04
期刊：
影响因子：
--
通讯作者：
Bridgman PC
中科院分区：
文献类型：
--
作者：
Chandrasekar I;Goeckeler ZM;Turney SG;Wang P;Wysolmerski RB;Adelstein RS;Bridgman PC
网格蛋白介导的内吞作用（CME）对于细胞功能包括营养摄取、受体介导的信号传导和膜再循环是必需的。CME中对肌动蛋白的需求仍不清楚，并且可能因膜张力的区域或细胞差异而变化。先前的研究已经调查了肌动蛋白聚合在抵消这种张力中的作用。在这里，我们研究的肌动蛋白马达蛋白，肌球蛋白II（MII），在组成型受体介导的内吞作用的作用。在来自胚胎MIIB敲除（MIIB KO）小鼠的成纤维细胞中，我们观察到CME的明显缺陷：转铁蛋白的内化显著降低，并且YFP-网格蛋白轻链的表面寿命增加。此外，急性blebbistatin治疗，以miMII，shRNA介导的敲低MIIB或MIIA，和治疗与nM latruculin A也抑制转铁蛋白摄取。MIIB KO细胞或用blebbistatin处理的细胞的电子显微镜显示浅包被小凹的百分比增加。此外，高度内陷的被膜凹坑是扭曲和不对称的。我们的研究结果表明，MII活动是至关重要的涂层坑进展过程中CME。MII功能的丧失导致网格蛋白依赖性内化的概率显著降低。我们得出结论，CME是肌动球蛋白依赖，并通过其在脚手架的作用，肌动蛋白支持MII驱动力的产生，调节膜弯曲和断裂。
Clathrin-mediated endocytosis (CME) is essential to cell functions including nutrient uptake, receptor-mediated signaling, and membrane recycling. The requirement for actin in CME remains unclear and may vary due to regional or cellular differences in membrane tension. Previous studies have investigated the role of actin polymerization in counteracting this tension. Here we examined the role of the actin motor protein, myosin II (MII), during constitutive receptor-mediated endocytosis. In fibroblasts from embryonic MIIB knockout (MIIB KO) mice, we observed clear defects in CME: internalization of transferrin was significantly decreased, and the surface lifetime of YFP-clathrin light chain was increased. In addition, acute blebbistatin treatment to inactivate MII, shRNA-mediated knockdown of MIIB or MIIA, and treatment with nM latruculin A also inhibited transferrin uptake. Electron microscopy of MIIB KO cells or cells treated with blebbistatin revealed an increased percentage of shallow coated pits. Moreover, highly-invaginated coated pits were distorted and asymmetric. Our results indicate that MII activity is critical for coated pit progression during CME. Loss of MII function results in significant decreases in the probability of clathrin-dependent internalization. We conclude that CME is actomyosin-dependent, and that through its role in scaffolding, actin supports MII-driven force generation that regulates membrane bending and scission.
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影响因子：
9.8
作者：
Loerke D;Mettlen M;Yarar D;Jaqaman K;Jaqaman H;Danuser G;Schmid SL
通讯作者：
Schmid SL
影响因子：
19
作者：
Diz-Muñoz A;Fletcher DA;Weiner OD
通讯作者：
Weiner OD
影响因子：
21.3
作者：
通讯作者：
--
影响因子：
64.5
作者：
Boucrot E;Pick A;Çamdere G;Liska N;Evergren E;McMahon HT;Kozlov MM
通讯作者：
Kozlov MM
影响因子：
2.9
作者：
Breuer, W;Cabantchik, ZI
通讯作者：
Cabantchik, ZI