A model for regulation of aurora B by Sds22 and PP1. The drawing shows a schematic model of the activation of aurora B kinase activity and its regulation by Sds22/PP1. Aurora B activates through autophosphorylation of phospho-T232 at the both the centromere and kinetochore. Phospho–aurora B can destabilize interactions between kinetochores and microtubules through phosphorylation of unknown targets. Sds22/PP1 dephosphorylates phospho–aurora B and, thus, indirectly functions to stabilize kinetochore–microtubule interactions. Centromere-associated aurora B may inhibit Sds22/PP1 when distance between centromere and kinetochore are low, e.g., in syntelic or merotelic attachments.