TY - JOUR
T1 - Proteomic analysis of microtubule inner proteins (MIPs) in Rib72 null Tetrahymena cells reveals functional MIPs
AU - Fabritius, Amy S.
AU - Bayless, Brian A.
AU - Li, Sam
AU - Stoddard, Daniel
AU - Heydeck, Westley
AU - Ebmeier, Christopher C.
AU - Anderson, Lauren
AU - Gunnels, Tess
AU - Nachiappan, Chidambaram
AU - Whittall, Justen B.
AU - Old, William
AU - Agard, David A.
AU - Nicastro, Daniela
AU - Winey, Mark
N1 - Publisher Copyright:
© 2021 Fabritius et al.
PY - 2021/11/1
Y1 - 2021/11/1
N2 - The core structure of motile cilia and flagella, the axoneme, is built from a stable population of doublet microtubules. This unique stability is brought about, at least in part, by a network of microtubule inner proteins (MIPs) that are bound to the luminal side of the microtubule walls. Rib72A and Rib72B were identified as MIPs in the motile cilia of the protist Tetrahymena thermophila. Loss of these proteins leads to ciliary defects and loss of additional MIPs. We performed mass spectrometry coupled with proteomic analysis and bioinformatics to identify the MIPs lost in RIB72A/B knockout Tetrahymena axonemes. 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.
AB - The core structure of motile cilia and flagella, the axoneme, is built from a stable population of doublet microtubules. This unique stability is brought about, at least in part, by a network of microtubule inner proteins (MIPs) that are bound to the luminal side of the microtubule walls. Rib72A and Rib72B were identified as MIPs in the motile cilia of the protist Tetrahymena thermophila. Loss of these proteins leads to ciliary defects and loss of additional MIPs. We performed mass spectrometry coupled with proteomic analysis and bioinformatics to identify the MIPs lost in RIB72A/B knockout Tetrahymena axonemes. 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.
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U2 - 10.1091/mbc.E20-12-0786
DO - 10.1091/mbc.E20-12-0786
M3 - Article
C2 - 34406789
AN - SCOPUS:85118902869
SN - 1059-1524
VL - 32
JO - Molecular biology of the cell
JF - Molecular biology of the cell
IS - 21
M1 - 0786
ER -