Electron cryo-tomography provides insight into procentriole architecture and assembly mechanism

Abstract
Data availability
Article and author information
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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

The following data sets were generated

(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9167.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9167
(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9168.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9168
(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9169.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9169
(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9170.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9170
(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9171.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9171
(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9172.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9172
(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9173.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9173
(2019) Electron cryo-tomography and subtomogram averaging of microtubule triplet from procentriole
Electron Microscopy Data Bank, EMD-9174.

http://www.ebi.ac.uk/pdbe/entry/emdb/EMD-9174

Article and author information

Author details

Sam Li

Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States

For correspondence
samli@msg.ucsf.edu

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0002-0210-8192
Jose-Jesus Fernandez

Macromolecular structures, Centro Nacional de Biotecnologia, CSIC, Madrid, Spain

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0003-2222-3355
Wallace F Marshall

Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States

Competing interests
The authors declare that no competing interests exist.
David A Agard

Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States

For correspondence
agard@msg.ucsf.edu

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0003-3512-695X

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.

Copyright

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.