Required for bipolar spindle formation and proper chromosome segregation. Has an indirect role in connecting the kinetochores and the plus end of pole to chromosome microtubules by targeting alp14 to the spindle pole body. Involved in the emergence of large microtubule organizing centers (MTOC) in interphase cells. Attaches to the minus ends of microtubules and associates with the sites of microtubule attachment on the nuclear envelope. This leads to the stabilzation of the microtubule bundles. Interacts with alp14. Associated with the equatorial MTOC, spindle midzones, spindle pole body and mitotic kinetochore periphery. Spindle and kinetochore localization is alp14-dependent.