Required for anaphase spindle elongation and microtubule bundling in both interphase and mitosis. Has a role in spatial and temporal regulation of septation and cytokinesis and ensures equal partition of segregating sister chromatids. Ensures correct midzone positioning of protein kinase ark1. Acts as a regulatory component at cytokinesis checkpoint where it inhibits nuclear division when actomyosin ring formation is impaired. Interacts with klp9. Localizes to microtubule overlapping zones during interphase and spindle midzone during anaphase. Belongs to the MAP65/ASE1 family.