Septins are GTPases involved in cytokinesis. In yeast, they form a ring at the cleavage site. Using FRAP, we show that septins are mobile within the ring at bud emergence and telophase and are immobile during S, G2, and M phases. Immobilization of the septins is dependent on both Cla4, a PAK-like kinase, and Gin4, a septin-dependent kinase that can phosphorylate the septin Shs1/Sep7. Induction of septin ring dynamics in telophase is triggered by the translocation of Rts1, a kinetochore-associated regulatory subunit of PP2A phosphatase, to the bud neck and correlates with Rts1-dependent dephosphorylation of Shs1. In rts1-Delta cells, the actomyosin ring contracts properly but cytokinesis fails. Together our results implicate septins in a late step of cytokinesis and indicate that proper regulation of septin dynamics, possibly through the control of their phosphorylation state, is required for the completion of cytokinesis.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|