PT  - JOURNAL ARTICLE
AU  - Thomas S. McAlear
AU  - Susanne Bechstedt
TI  - The mitotic spindle protein CKAP2 potently increases formation and stability of microtubules
AID  - 10.1101/2021.07.20.453056
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.07.20.453056
4099  - http://biorxiv.org/content/early/2021/07/20/2021.07.20.453056.short
4100  - http://biorxiv.org/content/early/2021/07/20/2021.07.20.453056.full
AB  - Cells increase microtubule dynamics to make large rearrangements to their microtubule cytoskeleton during cell division. Changes in microtubule dynamics are essential for the formation and function of the mitotic spindle, and misregulation can lead to aneuploidy and cancer. Using in vitro reconstitution assays we show that the mitotic spindle protein Cytoskeleton-Associated Protein 2 (CKAP2) has a strong effect on nucleation of microtubules by lowering the critical tubulin concentration 100-fold. CKAP2 increases the apparent rate constant ka of microtubule growth by 50-fold and increases microtubule growth rates. In addition, CKAP2 strongly suppresses catastrophes. Our results identify CKAP2 as the most potent microtubule growth factor to date. These finding help explain CKAP2s role as an important spindle protein, proliferation marker, and oncogene.Competing Interest StatementThe authors have declared no competing interest.