Ensures chromosome alignment and accurate chromosome segregation during mitosis. Promotes proper kinetochore-microtubule (k-MT) interactions during anaphase B. The phosphorylation status of nsk1 affects the proper k-MT coupling, ensuring that it interacts stably only at the correct time during mitosis. Interacts with dlc1. The dlc1-nsk1 complex seems to oligomerize in chain-like structures. Also binds directly to spindle microtubules. Undergoes cell cycle-dependent localization changes, nucleolar during interphase, distributed in the nucleoplasm during metaphase, and increased at kinetochores and the spindle during anaphase. Phosphorylated by cdk1 at prometaphase arrest. Phosphorylation prevents nsk1 kinetochore and spindle targeting. Dephosphorylated by clp1 at anaphase onset controls its relocalization.