Chai Pengxin, Yang Jun, Geohring Indigo C, Markus Steven M, Wang Yue, Zhang Kai
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.
Nat Struct Mol Biol. 2025 Apr 22. doi: 10.1038/s41594-025-01543-3.
Dynein-driven cargo transport has a pivotal role in diverse cellular activities, central to which is dynein's mechanochemical cycle. Here, we performed a systematic cryo-electron microscopic investigation of the conformational landscape of full-length human dynein 1 in reaction, in various nucleotide conditions, on and off microtubules. Our approach reveals over 40 high-resolution structures, categorized into eight states, providing a dynamic and comprehensive view of dynein throughout its mechanochemical cycle. The described intermediate states reveal mechanistic insights into dynein function, including a 'backdoor' phosphate release model that coordinates linker straightening, how microtubule binding enhances adenosine triphosphatase activity through a two-way communication mechanism and the crosstalk mechanism between AAA1 and the regulatory AAA3 site. Our findings also lead to a revised model for the force-generating powerstroke and reveal means by which dynein exhibits unidirectional stepping. These results improve our understanding of dynein and provide a more complete model of its mechanochemical cycle.
动力蛋白驱动的货物运输在多种细胞活动中起着关键作用，其中核心是动力蛋白的机械化学循环。在这里，我们对全长人动力蛋白1在反应中、在各种核苷酸条件下、在微管上和微管外的构象景观进行了系统的冷冻电子显微镜研究。我们的方法揭示了40多种高分辨率结构，分为八个状态，提供了动力蛋白在其整个机械化学循环中的动态和全面视图。所描述的中间状态揭示了动力蛋白功能的机制见解，包括协调连接蛋白伸直的“后门”磷酸盐释放模型、微管结合如何通过双向通信机制增强三磷酸腺苷酶活性以及AAA1和调节性AAA3位点之间的串扰机制。我们的发现还导致了产生力的动力冲程的修订模型，并揭示了动力蛋白表现出单向步进的方式。这些结果增进了我们对动力蛋白的理解，并提供了其机械化学循环的更完整模型。
