Microtubules acquire resistance from mechanical breakage through intralumenal acetylation

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Science  21 Apr 2017:
Vol. 356, Issue 6335, pp. 328-332
DOI: 10.1126/science.aai8764

Acetylation keeps microtubules strong

Cells need microtubules for intracellular transport and to avoid being crushed. On investigating microtubule breakage in live fibroblasts, Xu et al. found that if they were not acetylated, long-lived microtubules underwent frequent rupture after buckling. Acetylation makes microtubules more mechanically stable, facilitates sliding between filaments, and makes the lattice more plastic.

Science, this issue p. 328


Eukaryotic cells rely on long-lived microtubules for intracellular transport and as compression-bearing elements. We considered that long-lived microtubules are acetylated inside their lumen and that microtubule acetylation may modify microtubule mechanics. Here, we found that tubulin acetylation is required for the mechanical stabilization of long-lived microtubules in cells. Depletion of the tubulin acetyltransferase TAT1 led to a significant increase in the frequency of microtubule breakage. Nocodazole-resistant microtubules lost upon removal of acetylation were largely restored by either pharmacological or physical removal of compressive forces. In in vitro reconstitution experiments, acetylation was sufficient to protect microtubules from mechanical breakage. Thus, acetylation increases mechanical resilience to ensure the persistence of long-lived microtubules.

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