Figure 10.

Model for Rae1 function in mitosis. We propose that Rae1 targets to unattached kinetochores at the onset of mitosis together with Bub1, just like Bub3. There, Rae1–Bub1 and Bub3–Bub1 proteins act to activate the mitotic checkpoint, potentially by producing anaphase wait signals. Unlike Rae1, Bub3 also interacts with BubR1 and localizes to the cytosolic component of the mitotic checkpoint complex that acts to inhibit the APC activator Cdc20 when anaphase wait signals are present. For simplicity, only part of the components of the checkpoint is shown in the model.