Formin mDia3: A novel target for Aurora B kinase.

Stable attachment of kinetochores to spindle microtubules is essential for accurate chromosome segregation. We have shown that a kinetochore-associated formin protein, mDia3, contributes to the generation of stable kinetochore-microtubule attachment. The published report reviewed here shows an essential role of mDia3 in achieving metaphase chromosome alignment, and this function is directly regulated by Aurora B phosphorylation. Aurora B is a central component during the capture of spindle microtubules by kinetochores, in which it selectively eliminates incorrect attachments by phosphorylating a group of microtubule binding proteins at kinetochores to reduce their microtubule binding affinity. Here, we discuss the roles of Aurora B kinase and its substrates in achieving proper kinetochore-microtubule attachment.