Kinesin-5 Promotes Microtubule Nucleation and Assembly by Stabilizing a Lattice-Competent Conformation of Tubulin.

ABSTRACT: Besides sliding apart antiparallel microtubules during spindle elongation, the mitotic kinesin-5, Eg5, promotes microtubule polymerization, emphasizing its importance in mitotic spindle length control. Here, we characterize the Eg5 microtubule polymerase mechanism by assessing motor-induced changes in the longitudinal and lateral tubulin-tubulin bonds that form the microtubule lattice. Isolated Eg5 motor domains promote microtubule nucleation, growth, and stability; thus, crosslinking tubulin by pairs of motor heads is not necessary for polymerase activity. Eg5 binds preferentially to microtubules over free tubulin, which contrasts with microtubule-depolymerizing kinesins that preferentially bind free tubulin over microtubules. Colchicine-like inhibitors that stabilize the bent conformatio

SUBMITTER: Chen GY 

PROVIDER: S-EPMC6684259 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature