Abstract

Cilia are ubiquitous eukaryotic organelles responsible for cellular motility and sensory functions. The ciliary axoneme is a microtubule-based cytoskeleton consisting of two central singlets and nine outer doublet microtubules. Cryo-electron microscopy-based studies have revealed a complex network inside the lumen of both tubules composed of microtubule-inner proteins (MIPs). However, the functions of most MIPs remain unknown. Here, we present single-particle cryo-EM-based analyses of the Tetrahymena thermophila native doublet microtubule and identify 42 MIPs. These data shed light on the evolutionarily conserved and diversified roles of MIPs. In addition, we identified MIPs potentially responsible for the assembly and stability of the doublet outer junction. Knockout of the evolutionarily conserved outer junction component CFAP77 moderately diminishes Tetrahymena swimming speed and beat frequency, indicating the important role of CFAP77 and outer junction stability in cilia beating generation and/or regulation.

Using cryo-EM, the authors identified 42 MIPs, including outer junction protein CFAP77 and outer dense fibers, in native doublet microtubules of Tetrahymena thermophila. Knockout of CFAP77 reduced ciliary beat frequency and led to outer junction damage.

Details

Title
Native doublet microtubules from Tetrahymena thermophila reveal the importance of outer junction proteins
Author
Kubo, Shintaroh 1 ; Black, Corbin S. 1   VIAFID ORCID Logo  ; Joachimiak, Ewa 2 ; Yang, Shun Kai 1 ; Legal, Thibault 1 ; Peri, Katya 1 ; Khalifa, Ahmad Abdelzaher Zaki 1 ; Ghanaeian, Avrin 1 ; McCafferty, Caitlyn L. 3 ; Valente-Paterno, Melissa 1 ; De Bellis, Chelsea 4 ; Huynh, Phuong M. 4 ; Fan, Zhe 4 ; Marcotte, Edward M. 3   VIAFID ORCID Logo  ; Wloga, Dorota 2 ; Bui, Khanh Huy 1   VIAFID ORCID Logo 

 McGill University, Department of Anatomy and Cell Biology, Montreal, Canada (GRID:grid.14709.3b) (ISNI:0000 0004 1936 8649); McGill University, Centre de Recherche en Biologie Structurale, Montreal, Canada (GRID:grid.14709.3b) (ISNI:0000 0004 1936 8649) 
 Nencki Institute of Experimental Biology of Polish Academy of Sciences, Laboratory of Cytoskeleton and Cilia Biology, Warsaw, Poland (GRID:grid.419305.a) (ISNI:0000 0001 1943 2944) 
 University of Texas, Department of Molecular Biosciences, Center for Systems and Synthetic Biology, Austin, USA (GRID:grid.55460.32) (ISNI:0000000121548364) 
 McGill University, Department of Anatomy and Cell Biology, Montreal, Canada (GRID:grid.14709.3b) (ISNI:0000 0004 1936 8649) 
Pages
2168
Publication year
2023
Publication date
2023
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2801413755
Copyright
© The Author(s) 2023. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.