Figure 8: Schematic model.
From: Cep57 is a Mis12-interacting kinetochore protein involved in kinetochore targeting of Mad1–Mad2
Cep57 is localized to kinetochores and interacts with Mis12 and Mad1. During the early stage of mitosis, the kinetochores are not attached by microtubules and induce SAC activation. The RZZ and Ndc80/Hec1 complexes are responsible for the accumulation of Mad1–Mad2 to kinetochores by direct or indirect means in human cells14,15,19,23. Cep57 also acts as one of the anchoring factors of the Mad1–Mad2 complex by the interaction with Mad1 at the kinetochores (top). When the kinetochores are captured by microtubules, Cep57 binds to microtubules along with other outer kinetochore proteins including Hec1, Nuf2 and KNL1 (refs 1, 30). Thus, Mad1–Mad2 is disassociated from the kinetochores, which results in SAC silencing (bottom). NT, N terminus. CT, C terminus.
