Mechanisms of cytokinesis in budding yeast.

Cytokinesis is essential for cell proliferation in all domains of life. Because the core components and mechanisms of cytokinesis are conserved from fungi to humans, the budding yeast Saccharomyces cerevisiae has served as an attractive model for studying this fundamental process. Cytokinesis in budding yeast is driven by two interdependent cellular events: actomyosin ring (AMR) constriction and the formation of a chitinous cell wall structure called the primary septum (PS), the functional equivalent of extracellular matrix remodeling during animal cytokinesis. AMR constriction is thought to drive efficient plasma membrane ingression as well as to guide PS formation, whereas PS formation is thought to stabilize the AMR during its constriction. Following the completion of the PS formation, two secondary septa (SS), consisting of glucans and mannoproteins, are synthesized at both sides of the PS. Degradation of the PS and a part of the SS by a chitinase and glucanases then enables cell separation. In this review, we discuss the mechanics of cytokinesis in budding yeast, highlighting its common and unique features as well as the emerging questions.