Divide and Prosper: Molecular Mechanisms and Consequences of Cytokinetic Ring Regulation

Abstract

In many organisms, a cytokinetic ring directs daughter cell separation following mitosis. While conserved molecular participants in this process have been defined, the signaling events controlling cytokinetic ring function remain obscure. Using a genetically-tractable fission yeast, Schizosaccharomyces pombe, I have investigated mechanisms involved in such signaling, with a particular interest in kinase and phosphatase networks. Through identification of a new subunit of the S. pombe chromosomal passenger complex, I have found that Aurora B kinase influences cytokinesis by mediating Cdc14-family phosphatase accumulation at the cytokinetic ring. In addition, I have discovered that Sid2, a kinase of the S. pombe septation initiation network, phosphorylates cytokinetic formin Cdc12 to reverse formin multimerization and allow cytokinetic ring maintenance. My studies also indicate that cytokinesis impacts cell cycle-dependent polarized growth, and that phosphosignaling at the cytokinetic ring ensures robust growth following cell division. These studies advance our understanding of molecular cues regulating cytokinesis, and broaden knowledge concerning the consequences of this control.