Chromokinesin KIF4A teams up with Stathmin 1 to regulate abscission in a SUMO-dependent manner

Abstract

Cell division ends when two daughter cells physically separate via abscission, the cleavage of the intercellular bridge. It is not clear how the anti-parallel microtubule bundles bridging daughter cells are severed. Here, we present a novel abscission mechanism. We identified the chromokinesin KIF4A adjacent to the midbody during cytokinesis which is required for efficient abscission. KIF4A is regulated by post-translational modifications. We evaluated modification of KIF4A by the ubiquitin-like protein SUMO. We mapped lysine 460 in KIF4A as the SUMO acceptor site and employed CRISPR-Cas9 mediated genome editing to block SUMO conjugation of endogenous KIF4A. Failure to SUMOylate this site in KIF4A delayed cytokinesis. SUMOylation of KIF4A enhances affinity for the microtubule destabilizer Stathmin1. We here present a new level of abscission regulation through the dynamic interactions between KIF4A and Stathmin 1 as controlled by SUMO modification of KIF4A.