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Cell. 2017 Jun 15;169(7):1303-1314.e18. doi: 10.1016/j.cell.2017.05.025. Epub 2017 Jun 8.

Cryo-EM Reveals How Human Cytoplasmic Dynein Is Auto-inhibited and Activated.

Author information

1
MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
2
Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany.
3
Department of Pediatric Neurology, Université Paris Descartes, Imaging Institute, INSERM U781, Paris, France.
4
MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK. Electronic address: cartera@mrc-lmb.cam.ac.uk.

Abstract

Cytoplasmic dynein-1 binds dynactin and cargo adaptor proteins to form a transport machine capable of long-distance processive movement along microtubules. However, it is unclear why dynein-1 moves poorly on its own or how it is activated by dynactin. Here, we present a cryoelectron microscopy structure of the complete 1.4-megadalton human dynein-1 complex in an inhibited state known as the phi-particle. We reveal the 3D structure of the cargo binding dynein tail and show how self-dimerization of the motor domains locks them in a conformation with low microtubule affinity. Disrupting motor dimerization with structure-based mutagenesis drives dynein-1 into an open form with higher affinity for both microtubules and dynactin. We find the open form is also inhibited for movement and that dynactin relieves this by reorienting the motor domains to interact correctly with microtubules. Our model explains how dynactin binding to the dynein-1 tail directly stimulates its motor activity.

KEYWORDS:

activation; auto-inhibition; cryo-EM; dynactin; dynein; microtubule; motor; phi-particle

PMID:
28602352
PMCID:
PMC5473941
DOI:
10.1016/j.cell.2017.05.025
[Indexed for MEDLINE]
Free PMC Article

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