The internal Cdc20 binding site in BubR1 facilitates both spindle assembly checkpoint signalling and silencing

Kinetochores that fail to form bipolar attachments to the mitotic spindle delay chromosome segregation by BubR1 mediated inhibition of Cdc20. Lischetti et al. show that BubR1 recruits Cdc20 to the kinetochore via a domain that mediates both checkpoint activation and silencing.