Microtubule-binding-induced allostery triggers LIS1 dissociation from dynein prior to cargo transport.
Microtubule-binding-induced allostery triggers LIS1 dissociation from dynein prior to cargo transport.
复制标题
微管结合诱导的变构会在货物运输之前触发 LIS1 从动力蛋白上解离。
DOI：
10.1038/s41594-023-01010-x
复制
发表时间：
2023
影响因子：
16.8
通讯作者：
Markus,StevenM
中科院分区：
文献类型：
--
作者：
Ton,WilliamD;Wang,Yue;Chai,Pengxin;Beauchamp-Perez,Cisloynny;Flint,NicholasT;Lammers,LindsayG;Xiong,Hao;Zhang,Kai;Markus,StevenM
lissencephaly-related protein LIS 1是细胞质动力蛋白的关键调节因子，其控制运动功能和细胞内定位（例如，微管加端）。尽管LIS 1结合是动力蛋白活性所必需的，但其在货物运输开始之前的解结合同样重要，因为防止解离导致动力蛋白功能障碍。为了了解动力蛋白-LIS 1结合是否以及如何被调节，我们设计了锁定在微管结合（MT-B）或微管未结合（MT-U）状态的动力蛋白突变体。而MT-B突变体表现出低的LIS 1亲和力，MT-U突变体结合LIS 1具有高亲和力，因此仍然几乎不可逆地与微管加端。我们发现，一个单体马达结构域是足以表现出这些相反的LIS 1亲和力，这是进化保守的酵母和人类之间。有和没有LIS 1的人动力蛋白的三个冷冻电镜结构揭示了微管结合诱导的构象变化负责这种调节。我们的工作揭示了LIS 1介导的动力蛋白激活的关键生化和结构见解。
The lissencephaly-related protein LIS1 is a critical regulator of cytoplasmic dynein that governs motor function and intracellular localization (for example, to microtubule plus-ends). Although LIS1 binding is required for dynein activity, its unbinding prior to initiation of cargo transport is equally important, since preventing dissociation leads to dynein dysfunction. To understand whether and how dynein–LIS1 binding is modulated, we engineered dynein mutants locked in a microtubule-bound (MT-B) or microtubule-unbound (MT-U) state. Whereas the MT-B mutant exhibits low LIS1 affinity, the MT-U mutant binds LIS1 with high affinity, and as a consequence remains almost irreversibly associated with microtubule plus-ends. We find that a monomeric motor domain is sufficient to exhibit these opposing LIS1 affinities, and that this is evolutionarily conserved between yeast and humans. Three cryo-EM structures of human dynein with and without LIS1 reveal microtubule-binding induced conformational changes responsible for this regulation. Our work reveals key biochemical and structural insight into LIS1-mediated dynein activation.