RT Journal Article
SR Electronic
T1 Liquid-liquid phase separation of the chromosomal passenger complex drives parallel bundling of midzone microtubules
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.01.07.475460
DO 10.1101/2022.01.07.475460
A1 Ewa Niedzialkowska
A1 Tan M. Truong
A1 Luke A. Eldredge
A1 Stefanie Redemann
A1 Denis Chretien
A1 P. Todd Stukenberg
YR 2022
UL http://biorxiv.org/content/early/2022/01/09/2022.01.07.475460.abstract
AB The spindle midzone is a dynamic structure that forms during anaphase, mediates chromosome segregation, and provides a signaling platform to position the cleavage furrow. The spindle midzone comprises two antiparallel bundles of microtubules (MTs) but the process of their formation is poorly understood. Here, we show that the Chromosomal Passenger Complex (CPC) undergoes liquid-liquid phase separation (LLPS) to generate parallel MT bundles in vitro when incubated with free tubulin and GTP. MT bundles emerge from CPC droplets with protruding minus-ends that then grow into long, tapered MT structures. During this growth, the CPC in condensates apparently reorganize to coat and bundle the resulting MT structures. CPC mutants attenuated for LLPS or MT binding prevented the generation of parallel MT bundles in vitro and reduced the number of MTs present at spindle midzones in HeLa cells. Our data uncovers a kinase-independent function of the CPC and provides models for how cells generate parallel-bundled MT structures that are important for the assembly of the mitotic spindle.Competing Interest StatementThe authors have declared no competing interest.