Elongator is a microtubule polymerase selective for poly-glutamylated tubulin: ELP456 to Tubulin crosslinking

ABSTRACT: Elongator is a tRNA-modifying complex regulating protein translation. Recently, a moonlighting function of Elongator has been identified in regulating the polarization of the microtubule cytoskeleton during asymmetric cell division. Elongator induces symmetry breaking of the anaphase midzone by selectively stabilizing microtubules on one side of the spindle, contributing to the downstream polarized segregation of cell-fate determinants and therefore to cell fate determination. Here, we show how Elongator controls microtubule dynamics. Elongator binds simultaneously to the tip of microtubules and also to free GTP-tubulin heterodimers using two different subcomplexes, Elp123 and Elp456, respectively. We show that these activities must be coupled for Elongator to decrease the critical concentration of tubulin for microtubule elongation. As a consequence, Elongator increases microtubule growth speed and decreases their catastrophe rate. Surprisingly, we found that Elp456 binds to tubulin tails and has strong selectivity towards polyglutamylated tubulin. Hence, microtubules assembled by Elongator become selectively enriched with polyglutamylated tubulin. Therefore, Elongator rewrites the tubulin code of growing microtubules, placing it at the core of cytoskeletal dynamics and polarization during asymmetric cell division.

INSTRUMENT(S):

ORGANISM(S): Drosophila Melanogaster (fruit Fly)

TISSUE(S): Cell Culture

SUBMITTER: Tomos Morgan  

LAB HEAD: Emmanuel Derivery

PROVIDER: PXD058480 | Pride | 2025-05-07

REPOSITORIES: Pride