Required for efficient abscission at the end of cytokinesis, together with components of the ESCRT-III complex. Homodimer. Interacts (via MIT domain) with CHMP1A, CHMP1B, CHMP2A and IST1. During cytokinesis, recruited to the midbody via interaction with CHMP1A. Interacts with membranes enriched in phosphoinositides. The C-terminal domain interacts with lipid membranes containing acidic phosphoinositides and is required for location at the midbody. The MIT domain interacts with the MIT-interacting motifs of several components of the ESCRT-III complex.