Cytoplasmic dynein is a microtubule motor protein which is responsible for the majority of minus end microtubule-based intracellular motility. The cargoes of dynein include not only mRNA and protein, but also cell organelle and vesicle. Dynactin, a huge complex with Mw of 1.2 Mda, is necessary for dynein's function. The subunits composition and an overall structure model of the dynactin has been revealed based on biochemistry and immuno-electron microscopy. Since the initial discovery, it has become clear that dynactin links dynein to cargo and increases dynein processivity. Although how dynactin ineracts with dynein and how dynactin act as an adapter between dynein and cargoes remain unclear, a lot of achievements have been made in the last decade. We will review these progresses and share a perspective future in this field.%胞质动力蛋白(cytoplasmic dynein)是沿微管向负极运动的马达蛋白,参与细胞内多种物质的运输,运输的货物(cargo)小至信使RNA和蛋白质,大至细胞器和囊泡.动力蛋白只有与动力激活蛋白(dynactin)结合在一起时才有活性.动力激活蛋白是一个分子量为1.2 MDa的多亚基复合物,利用分子生物学和免疫电子显微镜技术,研究者已阐明了其亚基的组成信息,并得到了一个初步的结构模型.10年来,随着对各亚基功能研究的不断深入,研究者发现动力激活蛋白不仅可以增强动力蛋白在微管上的运动持续性,而且还可帮助其结合细胞内的其他成分.然而,动力激活蛋白与动力蛋白之间如何相互调节功能,动力激活蛋白作为接头蛋白如何控制货物在动力蛋白上的结合与解离,这两个核心问题尚未解决.本文就动力激活蛋白的亚基组成及其辅助动力蛋白发挥功能等研究成果进行总结,并对以后的研究趋势进行展望.
展开▼
