UMMS Affiliation

Department of Radiology, Division of Cell Biology and Imaging

Publication Date


Document Type



Amino Acids, Peptides, and Proteins | Biophysics | Cell Biology | Genetic Phenomena | Genetics and Genomics | Molecular Biology | Structural Biology


Nearly all motile cilia contain a central apparatus (CA) composed of two connected singlet microtubules with attached projections that play crucial roles in regulating ciliary motility. Defects in CA assembly usually result in motility-impaired or paralyzed cilia, which in humans causes disease. Despite their importance, the protein composition and functions of the CA projections are largely unknown. Here, we integrated biochemical and genetic approaches with cryo-electron tomography to compare the CA of wild-type Chlamydomonas with CA mutants. We identified a large ( > 2 MD) complex, the C1a-e-c supercomplex, that requires the PF16 protein for assembly and contains the CA components FAP76, FAP81, FAP92, and FAP216. We localized these subunits within the supercomplex using nanogold labeling and show that loss of any one of them results in impaired ciliary motility. These data provide insight into the subunit organization and 3D structure of the CA, which is a prerequisite for understanding the molecular mechanisms by which the CA regulates ciliary beating.


Structural Biology, Migration, Motility, Cilia, Biophysics

Rights and Permissions

© 2019 Fu et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at

DOI of Published Version



J Cell Biol. 2019 Oct 31. pii: jcb.201906006. doi: 10.1083/jcb.201906006. [Epub ahead of print] Link to article on publisher's site

Journal/Book/Conference Title

The Journal of cell biology

Related Resources

Link to Article in PubMed

PubMed ID