The actin-binding and bundling protein, EPLIN, is required for cytokinesis

Cytokinesis involves two phases: (1) membrane ingression followed by (2) membrane abscission. The ingression phase generates a cleavage furrow and this requires co-operative function of the actin-myosin II contractile ring and septin filaments. We demonstrate that the actin-binding protein, EPLIN, locates to the cleavage furrow during cytokinesis and this is possibly via association with the contractile ring components, myosin II and the septin, Sept2. Depletion of EPLIN results in formation of multinucleated cells and this is associated with inefficient accumulation of active myosin II (MRLC(S19)) and Sept2 and their regulatory small GTPases, RhoA and Cdc42, respectively, to the cleavage furrow during the final stages of cytokinesis. We suggest that EPLIN may function during cytokinesis to maintain local accumulation of key cytokinesis proteins at the furrow.