Proteomic analysis of microtubule inner proteins (MIPs) in Rib72 null Tetrahymena cells reveals functional MIPs
Year: 2021
Type: article
Abstract: Motile cilia and flagella are built from stable populations of doublet microtubules that comprise their axonemes. Their unique stability is brought about, at least in part, by a network of M icrotubule I nner P roteins (MIPs) found in the lumen of their doublet microtubules. Rib72A and Rib72B were identified as microtubule inner proteins (MIPs) in the motile cilia of Tetrahymena thermophila . Loss of these proteins leads to ciliary defects and loss of multiple MIPs. We performed mass spectrometry coupled with proteomic analysis and bioinformatics to identify the MIPs lost in RIB72A/B knockout (KO) Tetrahymena cells. From this analysis we identified a number of candidate MIPs and pursued one, Fap115, for functional characterization. We find that loss of Fap115 results in disrupted cell swimming and aberrant ciliary beating. Cryo-electron tomography reveals that Fap115 localizes to MIP6a in the A-tubule of the doublet microtubules. Overall, our results highlight the complex relationship between MIPs, ciliary structure, and ciliary function.
Source: Molecular Biology of the Cell
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
Awards: G172750515, Structure and Mechanism: Hsp90 proteostasis, cilia biogenesis and the jumbo phage “nucleus”, G2756284711, Acquisition of an electron microscope for high-resolution single particle cryo-EM, G3611247453, Identification and functional analysis of A-tubule MIPs, G6035979156, Linux cluster for near atomic resolution single particle cryo-EM, G8549241093, MIPS (Microtubule Inner Proteins) function in cilia and basal bodies, Structure and Function of Complexes that Regulate Ciliary Motility
OpenAlex ID: W3194702254