Crucial regulator of the mitotic cell cycle and development. At prophase, required for dynein anchoring to the nuclear envelope important for proper centrosome-nucleus coupling. At G2/M phase, may be required for proper spindle formation and execution of cytokinesis. Probable component of the Integrator (INT) complex, a complex involved in the small nuclear RNAs (snRNA) U1 and U2 transcription and in their 3'-box-dependent processing (By similarity). Plays a role in gastrulation and early embryogenesis (By similarity). Nuclear location is required for recruitment of dynein motors to nuclear envelope at G2/M. Belongs to the asunder family.