An antiparallel actin dimer is associated with the endocytic pathway in mammalian cells
An antiparallel actin dimer is associated with the endocytic pathway in mammalian cells
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DOI：
10.1016/j.jsb.2011.09.010
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发表时间：
2012-01-01
影响因子：
3
通讯作者：
Schoenenberger, Cora-Ann
中科院分区：
文献类型：
--
作者：
Silvan, Unai;Boiteux, Celine;Schoenenberger, Cora-Ann
肌动蛋白细胞骨架的动态重排在细胞运动、内吞、RNA加工和染色质组织等过程中起着关键作用。然而，在不同的过程中所涉及的超分子肌动蛋白结构仍然在很大程度上是未知的。肌动蛋白的一种研究较少的形式是较低的二聚体（LD）。两个肌动蛋白分子以反平行方向的这种非常规排列可以通过体外聚合开始时的化学交联来检测。此外，证据表明，一个短暂的掺入LD到不断增长的细丝和它的能力，以抑制成核的F-肌动蛋白丝组装暗示，LD途径有助于超分子肌动蛋白图案。然而，这种肌动蛋白与特定细胞功能的明确联系尚未建立。我们已经开发了一种抗体，选择性地结合到LD配置在体外组装的超分子肌动蛋白结构。这种抗体使我们能够揭示不同哺乳动物细胞中的LD。特别是，我们显示了关联的反平行肌动蛋白的安排与内吞隔室在细胞和超微结构水平。两者合计，我们的研究结果强烈支持LD在哺乳动物细胞中的超分子肌动蛋白组件的图案化中的功能作用。(C)2011 Elsevier Inc. All rights reserved.
The dynamic rearrangement of the actin cytoskeleton plays a key role in several cellular processes such as cell motility, endocytosis, RNA processing and chromatin organization. However, the supramolecular actin structures involved in the different processes remain largely unknown. One of the less studied forms of actin is the lower dimer (LD). This unconventional arrangement of two actin molecules in an antiparallel orientation can be detected by chemical crosslinking at the onset of polymerization in vitro. Moreover, evidence for a transient incorporation of LD into growing filaments and its ability to inhibit nucleation of F-actin filament assembly implicate that the LD pathway contributes to supramolecular actin patterning. However, a clear link from this actin species to a specific cellular function has not yet been established. We have developed an antibody that selectively binds to LD configurations in supramolecular actin structures assembled in vitro. This antibody allowed us to unveil the LD in different mammalian cells. In particular, we show an association of the antiparallel actin arrangement with the endocytic compartment at the cellular and ultrastructural level. Taken together, our results strongly support a functional role of LD in the patterning of supramolecular actin assemblies in mammalian cells. (C) 2011 Elsevier Inc. All rights reserved.