Electron cryo-tomography provides insight into procentriole architecture and assembly mechanism
Abstract
Centriole is an essential structure with multiple functions in cellular processes. Centriole biogenesis and homeostasis is tightly regulated. Using electron cryo-tomography (cryoET) we present the structure of procentrioles from Chlamydomonas reinhardtii. We identified a set of non-tubulin components attached to the triplet microtubule (MT), many are at the junctions of tubules likely to reinforce the triplet. We describe structure of the A-C linker that bridges neighboring triplets. The structure infers that POC1 is likely an integral component of A-C linker. Its conserved WD40 β-propeller domain provides attachment sites for other A-C linker components. The twist of A-C linker results in an iris diaphragm-like motion of the triplets in the longitudinal direction of procentriole. Finally, we identified two assembly intermediates at the growing ends of procentriole allowing us to propose a model for the procentriole assembly. Our results provide a comprehensive structural framework for understanding the molecular mechanisms underpinning procentriole biogenesis and assembly.
Data availability
8 structures based on the subtomogram averaging have been deposited in the EMDB under the accession codes: EMD-9167, EMD-9168, EMD-9169, EMD-9170, EMD-9171, EMD-9172, EMD-9173, EMD-9174
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9167.
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9168.
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9169.
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9170.
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9171.
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9172.
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9173.
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Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentrioleElectron Microscopy Data Bank, EMD-9174.
Article and author information
Author details
Funding
Howard Hughes Medical Institute
- David A Agard
National Institutes of Health (GM031627)
- David A Agard
National Institutes of Health (GM118099)
- David A Agard
National Institutes of Health (PO1 GM105537)
- David A Agard
National Institutes of Health (GM113602)
- Wallace F Marshall
Fundacion Ramon Areces
- Jose-Jesus Fernandez
Spanish AEI/FEDER (SAF2017-84565-R)
- Jose-Jesus Fernandez
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Sriram Subramaniam, University of British Columbia, Canada
Version history
- Received: November 6, 2018
- Accepted: February 10, 2019
- Accepted Manuscript published: February 11, 2019 (version 1)
- Version of Record published: February 21, 2019 (version 2)
Copyright
© 2019, Li et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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