Multiciliated cells (MCCs) on mucociliary epithelium have important roles to generate the directional fluid flow by coordinated movement of several hundreds of motile cilia, and their motility defect is linked to several clinical symptoms in human, such as chronic respiratory infections, increased risks of hydrocephalus and female infertility. Although there were several genes reported to regulate the motility of multi-cilia on MCCs, without perturbing the cilia formation, the protein composition changes inside the organelle by motility defect were not revealed yet.
Based on the mucociliary epithelium of the Xenopus embryos as a model system, we recently published the simple method to isolate almost intact whole ciliary structures for label-free shotgun proteomics and identified 1,009 vertebrate conserved ciliary proteins. Expanding this approach, here we reported the ciliary proteome of motility-defective multiciliated cells. By suppressing the expression of two different genes involved in cilia motility regulation, we identified about a hundred ciliary proteins differentially abundant (either by expression or localization change) compared to those in the normal cilia. Among them, 35 proteins including proteins for outer dynein arm complex, energy production, were commonly changed regardless of their genetic background, which may be specifically involved in cilia motility, not in ciliogenesis.
By providing the protein changes inside the organelle, this result will provide new insight to understand how cilia motility is regulated. The detailed validation results also will be presented.