Wu Xufeng, Xiang Xin, Hammer John A
Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Trends Cell Biol. 2006 Mar;16(3):135-43. doi: 10.1016/j.tcb.2006.01.004. Epub 2006 Feb 15.
The plus-end of the microtubule has a central role in the interactions that occur between the microtubule and actin cytoskeletons. The recent identification of a family of proteins that congregate at the plus-end is enabling an increased mechanistic understanding of how this cross talk is accomplished. These proteins, termed plus-end tracking proteins because they appear to associate with the plus-end as it grows, have already been shown to regulate microtubule dynamics and to facilitate the formation of connections between the plus-end and the actin-rich cortex. Several motor proteins, including an actin-based motor, microtubule-based motors that move towards either end of the microtubule and microtubule motors that depolymerize microtubule ends, can now be added to the list of plus-end tracking proteins. Here, we discuss how the presence of these motors at the plus-end seems to drive several fundamental cellular processes involving force generation at the interface between microtubule ends and the cortex, vesicle translocation following search and capture, microtubule disassembly and the delivery of signals to the cortex that govern actin assembly and cell polarity.
微管的正端在微管与肌动蛋白细胞骨架之间的相互作用中起着核心作用。最近发现了一类聚集在正端的蛋白质，这使得人们对这种相互作用是如何实现的有了更多的机制性理解。这些蛋白质被称为正端追踪蛋白，因为它们似乎随着正端的生长而与之结合，已经被证明可以调节微管动力学，并促进正端与富含肌动蛋白的皮层之间连接的形成。现在，包括一种基于肌动蛋白的马达蛋白、向微管两端移动的基于微管的马达蛋白以及使微管末端解聚的微管马达蛋白在内的几种马达蛋白也被列入了正端追踪蛋白的名单。在这里，我们讨论了这些马达蛋白在正端的存在似乎如何驱动几个基本的细胞过程，包括在微管末端与皮层的界面处产生力、搜索和捕获后的囊泡转运、微管解聚以及向皮层传递控制肌动蛋白组装和细胞极性的信号。
