ADF/cofilin use an intrinsic mode of F-actin instability to disrupt actin filaments.
ADF/cofilin use an intrinsic mode of F-actin instability to disrupt actin filaments.
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DOI：
10.1083/jcb.200308144
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发表时间：
2003-12-08
影响因子：
7.8
通讯作者：
Egelman, Edward H
中科院分区：
文献类型：
--
作者：
Galkin, Vitold E;Orlova, Albina;VanLoock, Margaret S;Shvetsov, Alexander;Reisler, Emil;Egelman, Edward H
肌动蛋白解聚因子/丝切蛋白（AC）家族的蛋白质对细胞肌动蛋白结构的快速重排至关重要。体外实验表明，它们在肌动蛋白丝的切割和解聚过程中均具有活性，但其详细作用机制尚不清楚。在体外条件下，肌动蛋白丝中的亚基可以发生踏车运动；ATP的水解驱动亚基在丝的一端添加，同时在另一端亚基丢失。我们利用电子显微镜和图像分析表明，AC分子有效地破坏了F - 肌动蛋白的一条螺旋链内原聚体之间的一种纵向连接。我们发现，在没有任何AC蛋白的情况下，肌动蛋白原聚体之间的这种相同纵向连接在肌动蛋白丝的解聚（尖端）端被破坏，但在聚合（带刺）端很明显。我们认为，AC蛋白利用F - 肌动蛋白内部不稳定性的内在机制来使细胞内的肌动蛋白丝解聚/切割。
Proteins in the ADF/cofilin (AC) family are essential for rapid rearrangements of cellular actin structures. They have been shown to be active in both the severing and depolymerization of actin filaments in vitro, but the detailed mechanism of action is not known. Under in vitro conditions, subunits in the actin filament can treadmill; with the hydrolysis of ATP driving the addition of subunits at one end of the filament and loss of subunits from the opposite end. We have used electron microscopy and image analysis to show that AC molecules effectively disrupt one of the longitudinal contacts between protomers within one helical strand of F-actin. We show that in the absence of any AC proteins, this same longitudinal contact between actin protomers is disrupted at the depolymerizing (pointed) end of actin filaments but is prominent at the polymerizing (barbed) end. We suggest that AC proteins use an intrinsic mechanism of F-actin's internal instability to depolymerize/sever actin filaments in the cell.