| Structural highlights
Function
[TBA1_CHLRE] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain. [CFA20_CHLRE] Cilium- and flagellum-specific protein that plays a role in axonemal structure organization and motility (PubMed:24259666, PubMed:24574454). Involved in the control of flagellar beating in an asymmetric and planar waveform (PubMed:24259666, PubMed:24574454). Stabilizes outer doublet microtubules (DMTs) of the axoneme and may work as a scaffold for intratubular proteins, such as tektin and PACRG, to produce the beak structures in DMT1, 5 and 6 (PubMed:24259666, PubMed:24574454). Not essential for flagellar assembly (PubMed:24574454).[1] [2] [FLTOP_CHLRE] May act as a regulator of cilium basal body docking and positioning in mono- and multiciliated cells.[UniProtKB:Q6P8X9] [TBB_CHLRE] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain.
Publication Abstract from PubMed
Microtubules are cytoskeletal structures involved in stability, transport and organization in the cell. The building blocks, the alpha- and beta-tubulin heterodimers, form protofilaments that associate laterally into the hollow microtubule. Microtubule also exists as highly stable doublet microtubules in the cilia where stability is needed for ciliary beating and function. The doublet microtubule maintains its stability through interactions at its inner and outer junctions where its A- and B-tubules meet. Here, using cryo-electron microscopy, bioinformatics and mass spectrometry of the doublets of Chlamydomonas reinhardtii and Tetrahymena thermophila, we identified two new inner junction proteins, FAP276 and FAP106, and an inner junction-associated protein, FAP126, thus presenting the complete answer to the inner junction identity and localization. Our structural study of the doublets shows that the inner junction serves as an interaction hub that involves tubulin post-translational modifications. These interactions contribute to the stability of the doublet and hence, normal ciliary motility.
The inner junction complex of the cilia is an interaction hub that involves tubulin post-translational modifications.,Khalifa AAZ, Ichikawa M, Dai D, Kubo S, Black CS, Peri K, McAlear TS, Veyron S, Yang SK, Vargas J, Bechstedt S, Trempe JF, Bui KH Elife. 2020 Jan 17;9. pii: 52760. doi: 10.7554/eLife.52760. PMID:31951202[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Meng D, Cao M, Oda T, Pan J. The conserved ciliary protein Bug22 controls planar beating of Chlamydomonas flagella. J Cell Sci. 2014 Jan 15;127(Pt 2):281-7. doi: 10.1242/jcs.140723. Epub 2013 Nov, 20. PMID:24259666 doi:http://dx.doi.org/10.1242/jcs.140723
- ↑ Yanagisawa HA, Mathis G, Oda T, Hirono M, Richey EA, Ishikawa H, Marshall WF, Kikkawa M, Qin H. FAP20 is an inner junction protein of doublet microtubules essential for both the planar asymmetrical waveform and stability of flagella in Chlamydomonas. Mol Biol Cell. 2014 May;25(9):1472-83. doi: 10.1091/mbc.E13-08-0464. Epub 2014, Feb 26. PMID:24574454 doi:http://dx.doi.org/10.1091/mbc.E13-08-0464
- ↑ Khalifa AAZ, Ichikawa M, Dai D, Kubo S, Black CS, Peri K, McAlear TS, Veyron S, Yang SK, Vargas J, Bechstedt S, Trempe JF, Bui KH. The inner junction complex of the cilia is an interaction hub that involves tubulin post-translational modifications. Elife. 2020 Jan 17;9. pii: 52760. doi: 10.7554/eLife.52760. PMID:31951202 doi:http://dx.doi.org/10.7554/eLife.52760
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