Fig. 8.

Model. In metaphase Cdc14 is trapped in the nucleolus, while at the onset of anaphase it diffuses into the nucleus. At this stage, as well as during previous cell cycle phases (not depicted), septins form a scaffolding collar at the bud neck that recruits cytokinesis factors, including CAR components. In late anaphase/telophase the mitotic exit network (MEN) promotes Cdc14 full release into the cytoplasm, which allows its recruitment also to SPBs (preferentially the bud-directed SPB) and brings about mitotic exit. MEN activity and SPB-localized Cdc14 then drive septin ring splitting, which is in turn an essential prerequisite for CAR contraction and septum formation. At the end of cytokinesis the Dma1 and Dma2 ubiquitin ligases contribute to shut-off MEN signaling at SPBs via ubiquitination of their scaffold Nud1. However, when overexpressed or constitutively bound to Nud1, Dma2 acts as a MEN potent inhibitor and interferes with MEN-dependent functions, mainly for what concerns cytokinesis and, to a lesser extent, mitotic exit. See text for details