May be implicated in endosomal trafficking, or microtubule dynamics, or both. Participates in cytokinesis. Interacts with ITCH and WWP1. Interacts (via MIT domain) with IST1; leading to the recruitment of SPART to midbodies. Transiently associated with endosomes. Colocalized with IST1 to the ends of Flemming bodies during cytokinesis. Ubiquitinated; ubiquitination does not require ITCH and WWP1.