Checkpoint Proteins Bub1 and Bub3 Delay Anaphase Onset in Response to Low Tension Independent of Microtubule-Kinetochore Detachment.

The spindle assembly checkpoint (SAC) delays anaphase onset until sister chromosomes are bound to microtubules from opposite spindle poles. Only then can dynamic microtubules produce tension across sister kinetochores. The interdependence of kinetochore attachment and tension has proved challenging to understanding SAC mechanisms.

The kinesin-8 Kip3 scales anaphase spindle length by suppression of midzone microtubule polymerization.

Mitotic spindle function is critical for cell division and genomic stability. During anaphase, the elongating spindle physically segregates the sister chromatids. However, the molecular mechanisms that determine the extent of anaphase spindle elongation remain largely unclear.