Calaxin stabilizes the docking of outer arm dyneins onto ciliary doublet microtubule in vertebrates

Abstract
Data availability
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Abstract

Outer arm dynein (OAD) is the main force generator of ciliary beating. Although OAD loss is the most frequent cause of human primary ciliary dyskinesia, the docking mechanism of OAD onto the ciliary doublet microtubule (DMT) remains elusive in vertebrates. Here, we analyzed the functions of Calaxin/Efcab1 and Armc4, the two of five components of vertebrate OAD-DC (docking complex), using zebrafish spermatozoa and cryo-electron tomography. Mutation of armc4 caused complete loss of OAD, whereas mutation of calaxin caused only partial loss of OAD. Detailed structural analysis revealed that calaxin^-/- OADs are tethered to DMT through DC components other than Calaxin, and that recombinant Calaxin can autonomously rescue the deficient DC structure and the OAD instability. Our data demonstrate the discrete roles of Calaxin and Armc4 in the OAD-DMT interaction, suggesting the stabilizing process of OAD docking onto DMT in vertebrates.

Data availability

The Source Data files contain the numerical data and raw gel images used to generate the figures.The maps generated in this study have been deposited in EMDB under the following accession numbers: EMD-34791, EMD-34792, EMD-34793, EMD-34794, EMD-34795, EMD-34796, EMD-34797, EMD-34798, EMD-34799, EMD-34800, EMD-34801, and EMD-34802.

The following data sets were generated

1. Yamaguchi H
2. Kikkawa M
(2023) Doublet microtubule of zebrafish sperm axoneme, WT
Electron Microscopy Data Bank, EMD-34791.

https://www.ebi.ac.uk/emdb/EMD-34791
1. Yamaguchi H
2. Kikkawa M
(2023) Radial spoke 1 of zebrafish sperm axoneme, WT
Electron Microscopy Data Bank, EMD-34792.

https://www.ebi.ac.uk/emdb/EMD-34792
1. Yamaguchi H
2. Kikkawa M
(2023) Radial spoke 2 of zebrafish sperm axoneme, WT
Electron Microscopy Data Bank, EMD-34793.

https://www.ebi.ac.uk/emdb/EMD-34793
1. Yamaguchi H
2. Kikkawa M
(2023) Radial spoke 3 of zebrafish sperm axoneme, WT
Electron Microscopy Data Bank, EMD-34794.

https://www.ebi.ac.uk/emdb/EMD-34794
1. Yamaguchi H
2. Kikkawa M
(2023) Doublet microtubule of zebrafish sperm axoneme, calaxin-/-, OAD+ class
Electron Microscopy Data Bank, EMD-34795.

https://www.ebi.ac.uk/emdb/EMD-34795
1. Yamaguchi H
2. Kikkawa M
(2023) Doublet microtubule of zebrafish sperm axoneme, calaxin-/-, OAD- class
Electron Microscopy Data Bank, EMD-34796.

https://www.ebi.ac.uk/emdb/EMD-34796
1. Yamaguchi H
2. Kikkawa M
(2023) Doublet microtubule of zebrafish sperm axoneme, armc4-/-
Electron Microscopy Data Bank, EMD-34797.

https://www.ebi.ac.uk/emdb/EMD-34797
1. Yamaguchi H
2. Kikkawa M
(2023) Outer arm dynein of zebrafish sperm axoneme, WT
Electron Microscopy Data Bank, EMD-34798.

https://www.ebi.ac.uk/emdb/EMD-34798
1. Yamaguchi H
2. Kikkawa M
(2023) Outer arm dynein of zebrafish sperm axoneme, WT, refined focusing on the docking complex
Electron Microscopy Data Bank, EMD-34799.

https://www.ebi.ac.uk/emdb/EMD-34799
1. Yamaguchi H
2. Kikkawa M
(2023) Outer arm dynein of zebrafish sperm axoneme, WT, 1 mM calcium condition, refined focusing on the docking complex
Electron Microscopy Data Bank, EMD-34800.

https://www.ebi.ac.uk/emdb/EMD-34800
1. Yamaguchi H
2. Kikkawa M
(2023) Outer arm dynein of zebrafish sperm axoneme, calaxin-/-, refined focusing on the docking complex
Electron Microscopy Data Bank, EMD-34801.

https://www.ebi.ac.uk/emdb/EMD-34801
1. Yamaguchi H
2. Kikkawa M
(2023) Outer arm dynein of zebrafish sperm axoneme, calaxin-/-, incubated with recombinant Calaxin protein, refined focusing on the docking complex
Electron Microscopy Data Bank, EMD-34802.

https://www.ebi.ac.uk/emdb/EMD-34802

Article and author information

Author details

Hiroshi Yamaguchi

Department of Cell Biology and Anatomy, University of Tokyo, Tokyo, Japan

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0002-8722-129X
Motohiro Morikawa

Department of Cell Biology and Anatomy, University of Tokyo, Tokyo, Japan

Competing interests
The authors declare that no competing interests exist.
Masahide Kikkawa

Department of Cell Biology and Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Tokyo, Japan

For correspondence
mkikkawa@m.u-tokyo.ac.jp

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0001-7656-8194

Funding

Japan Society for the Promotion of Science (KAKENHI Grant Number 16H02502)

Masahide Kikkawa

Japan Society for the Promotion of Science (KAKENHI Grant Number 21H04762)

Masahide Kikkawa

Japan Agency for Medical Research and Development (Grant Number JP22ama121002j001)

Masahide Kikkawa

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.