Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA.
Curr Opin Cell Biol. 2010 Feb;22(1):88-95. doi: 10.1016/j.ceb.2009.10.009. Epub 2009 Dec 1.
Recent experiments reconstituting microtubule plus end tracking activity coupled with structural determination of microtubule plus end domains and plus end complexes are revealing the hierarchy, regulatory features, and potential mechanisms of plus end tracking proteins. Primary plus end tracking proteins include EB1 and XMAP215, while a host of secondary, EB1-dependent plus end proteins have been identified and characterized, including CLIP-170 and SKIP-motif proteins. Single molecule in vitro reconstitution assays show that XMAP215 is a processive polymerases that drives tubulin polymerization. Analysis of the EB1-microtubule interaction indicates EB1 actively promotes A-form microtubule lattice growth and rapidly exchanges with subsecond dwell times.
最近的实验重新构建了微管末端追踪活性，同时确定了微管末端结构域和末端复合物，揭示了末端追踪蛋白的层次结构、调节特征和潜在机制。主要的微管末端追踪蛋白包括 EB1 和 XMAP215，而许多次要的、依赖 EB1 的微管末端蛋白已被鉴定和表征，包括 CLIP-170 和 SKIP 基序蛋白。体外单分子重建实验表明，XMAP215 是一种有活性的聚合酶，能驱动微管蛋白聚合。对 EB1-微管相互作用的分析表明，EB1 能积极促进 A 型微管晶格生长，并能以亚秒级的停留时间快速交换。
