Finishing the job: cytoskeletal and membrane events bring cytokinesis to an end

Cytokinesis ensures the proper division of newly forming daughter cells. Failures in cytokinesis lead to multinucleated cells and compromise their genomic and cellular integrity. Research into the mechanism of cytokinesis has largely focuscd on understanding the timing, placement, and function of the actomyosin contractile ring that physically divides mitotic cells. However, there is growing evidence, which shows that even after mitotic cells have been nearly separated by the ingression of the contractile ring, they fail to separate if they cannot complete the final stages of cytokinesis. Recent studies have identified a number of proteins and events that art! essential for the completion of cytokinesis in mammalian cells and highlighted a role for membrane remodeling events late during cytokinesis. In this review, we discuss the molecules required for this process and describe how they may contribute to the individual steps that mediate the end of cytokinesis. (C) 2004 Elsevier Inc. All rights reserved.