RT Journal Article
SR Electronic
T1 Structural organization of the C1a-e-c supercomplex within the ciliary central apparatus
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 773416
DO 10.1101/773416
A1 Gang Fu
A1 Lei Zhao
A1 Erin Dymek
A1 Yuqing Hou
A1 Kangkang Song
A1 Nhan Phan
A1 Zhiguo Shang
A1 Elizabeth F. Smith
A1 George B. Witman
A1 Daniela Nicastro
YR 2019
UL http://biorxiv.org/content/early/2019/09/18/773416.abstract
AB 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 MDa) 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 three-dimensional (3D) structure of the CA, which is a prerequisite for understanding the molecular mechanisms by which the CA regulates ciliary beating.Summary Fu et al. use a wild-type vs. mutant comparison and cryo-electron tomography of Chlamydomonas flagella to identify central apparatus (CA) subunits and visualize their location in the native 3D CA structure. The study provides a better understanding of the CA and how it regulates ciliary motility.