Actin, microtubule, septin and ESCRT filament remodeling during late steps of cytokinesis

Abstract

Cytokinesis is the process by which a mother cell is physically cleaved into two daughter cells. In animal cells, cytokinesis begins with the contraction of a plasma membrane-associated actomyosin ring that is responsible for the ingression of a cleavage furrow. However, the post-furrowing steps of cytokinesis are less understood. Here, we highlight key recent findings that reveal a profound remodeling of several classes of cytoskeletal elements and cytoplasmic filaments (septins, microtubules, actin and ESCRT) in the late steps of cytokinesis. We review how this remodeling is required first for the stabilization of the intercellular bridge connecting the daughter cells and then for the steps leading up to abscission. New players regulating the abscission (NoCut) checkpoint, which delays abscission via cytoskeleton and ESCRT remodeling in response to various cytokinetic stresses, will also be emphasized. Altogether, the latest discoveries reveal a crucial role for posttranslational modifications of the cytoskeleton (actin oxidation, septin SUMOylation) and an unexpected requirement of ESCRT-III polymer dynamics for successful abscission.