Tubulin acetyltransferases access and modify the microtubule luminal K40 residue through anchors in taxane-binding pockets.

Autor: Luo J; School of Biomedical Sciences, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China., Lam WH; School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China. hl1988@hku.hk., Yu D; Department of Chemistry, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China., Chao VC; School of Biomedical Sciences, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China., Zopfi MN; School of Biomedical Sciences, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China., Khoo CJ; School of Biomedical Sciences, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China., Zhao C; School of Biomedical Sciences, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China., Yan S; School of Biomedical Sciences, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China., Liu Z; Department of Chemistry, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China., Li XD; Department of Chemistry, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China., Zheng C; School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China., Zhai Y; School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China. zhai@hku.hk., Ti SC; School of Biomedical Sciences, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China. jeffti@hku.hk.
Jazyk: angličtina
Zdroj: Nature structural & molecular biology [Nat Struct Mol Biol] 2024 Nov 04. Date of Electronic Publication: 2024 Nov 04.
DOI: 10.1038/s41594-024-01406-3
Abstrakt: Acetylation at α-tubulin K40 is the sole post-translational modification preferred to occur inside the lumen of hollow cylindrical microtubules. However, how tubulin acetyltransferases access the luminal K40 in micrometer-long microtubules remains unknown. Here, we use cryo-electron microscopy and single-molecule reconstitution assays to reveal the enzymatic mechanism for tubulin acetyltransferases to modify K40 in the lumen. One tubulin acetyltransferase spans across the luminal lattice, with the catalytic core docking onto two α-tubulins and the enzyme's C-terminal domain occupying the taxane-binding pockets of two β-tubulins. The luminal accessibility and enzyme processivity of tubulin acetyltransferases are inhibited by paclitaxel, a microtubule-stabilizing chemotherapeutic agent. Characterizations using recombinant tubulins mimicking preacetylated and postacetylated K40 show the crosstalk between microtubule acetylation states and the cofactor acetyl-CoA in enzyme turnover. Our findings provide crucial insights into the conserved multivalent interactions involving α- and β-tubulins to acetylate the confined microtubule lumen.
(© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)
Databáze: MEDLINE
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