Microtubule-severing activity in M phase.

The stable cytoplasmic microtubules that emanate from centrosomes in eukaryotic cells disappear at the onset of M phase and are replaced by the dynamic microtubules of the mitotic spindle. Microtubule-severing activity increases significantly under the control of maturation-promoting factor at the transition between G2 phase and M phase, and is thought to be involved in the microtubule reorganization. This review highlights three microtubule-severing factors that may be responsible for microtubule-severing activity in M phase.