Microtubule-dependent motor that is involved in microtubule organization in the mitotic spindle. Required for the polarization of interphase microtubules where it orients the microtubule plus ends toward the cell ends and the minus ends toward the cell center. Mediates minus end-directed sliding of cytoplasmic microtubules relative to each other; thereby promoting mitotic spindle disassembly. {ECO:0000269|PubMed:11694582; ECO:0000269|PubMed:16002618}.