Microtubule-binding-induced allostery triggers LIS1 dissociation from dynein prior to cargo transport

WD Ton and Y Wang and PX Chai and C Beauchamp-Perez and NT Flint and LG Lammers and H Xiong and K Zhang and SM Markus, NATURE STRUCTURAL & MOLECULAR BIOLOGY, 30, 1365-+ (2023).

DOI: 10.1038/s41594-023-01010-x

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. LIS1 is a critical activator of dynein- mediated retrograde transport. Ton et al. reveal that microtubule binding by dynein initiates a cascade of structural changes that trigger LIS1 dissociation from dynein prior to transport, providing insights into dynein activation.

Return to Publications page