Plk1 is associated with the centrosomes early in mitosis (Golsteyn et al. 1995). Plk1 activity is necessary for the maturation of centrosomes at the G2/M transition and the establishment of a bipolar spindle (Lane and Nigg 1996). Specific inhibitors against Plk1 or silencing of Plk1 produce a monopolar mitotic apparatus (Sumara et al, 2004, van Vugt et al, 2004, McInnes et al, 2006, Peters et al, 2006, Lénárt et al, 2007).
