Mechanistic insights into anchoring the cytokinetic ring

Abstract

Cytokinesis is the final step in cell division in which two daughter cells physically separate. In order to complete this process, many eukaryotes, including Schizosaccharomyces pombe, assemble an actin- and myosin-based cytokinetic ring (CR) in close proximity to the plasma membrane that constricts to bring together opposing membranes. Decades of work utilizing S. pombe have provided a complete parts list of the proteins required to build and assemble the CR, the order in which they arrive, and the number of each within the CR. However, there is far less known about how the CR is anchored to the plasma membrane, even though proper CR-plasma membrane attachment is crucial for maintaining genomic integrity. This work highlights two key mechanisms that promote CR-membrane anchoring – the role of the plasma membrane lipid PI(4,5)P2 in promoting central anchorage of the CR during cytokinesis, and the scaffolding roles of the membrane-binding Cdc15 F-BAR domain. Together, these studies represent a key advancement in our understanding of how components of both the plasma membrane and the proteins that bind it cooperate to promote robust CR anchoring.