Fission Yeast Cyclin-Dependent Kinase, Cdc2, Regulates the Mid1 Scaffolding Protein During Cytokinesis
Presentation Type
Poster/Portfolio
Presenter Major(s)
Cell and Molecular Biology
Mentor Information
Dawn Clifford Hart
Department
Cell and Molecular Biology
Location
Kirkhof Center KC63
Start Date
11-4-2012 9:00 AM
Keywords
Life Science
Abstract
Cytokinesis is the final stage of cell division and relies on a highly conserved actin-myosin contractile ring to separate one cell into two. The conserved protein Mid1 is critical as the initial organizer and anchors the structure to the cell membrane. Mid1 mutants show severe defects in contractile ring assembly and placement. Coincident with contractile ring formation, Mid1 is hyper-phosphorylated by multiple mitotic kinases. Mid1 phosphorylation by the cyclin dependent kinase, Cdc2, at both the N- and C-terminus facilitates the phosphorylation of Mid1 by the polo like kinase, Plo1. Fission yeast cells expressing Mid1 phosphosite mutations show sensitivity to low dose treatments of an actin depolymerizer, and cells bypass the mitotic spindle checkpoint. Surprisingly cells that bypass an active mitotic spindle checkpoint continue through mitosis, but fail to fully separate. This research highlights a regulatory role for Plo1 and Mid1 in early and late stages of cytokinesis.
Fission Yeast Cyclin-Dependent Kinase, Cdc2, Regulates the Mid1 Scaffolding Protein During Cytokinesis
Kirkhof Center KC63
Cytokinesis is the final stage of cell division and relies on a highly conserved actin-myosin contractile ring to separate one cell into two. The conserved protein Mid1 is critical as the initial organizer and anchors the structure to the cell membrane. Mid1 mutants show severe defects in contractile ring assembly and placement. Coincident with contractile ring formation, Mid1 is hyper-phosphorylated by multiple mitotic kinases. Mid1 phosphorylation by the cyclin dependent kinase, Cdc2, at both the N- and C-terminus facilitates the phosphorylation of Mid1 by the polo like kinase, Plo1. Fission yeast cells expressing Mid1 phosphosite mutations show sensitivity to low dose treatments of an actin depolymerizer, and cells bypass the mitotic spindle checkpoint. Surprisingly cells that bypass an active mitotic spindle checkpoint continue through mitosis, but fail to fully separate. This research highlights a regulatory role for Plo1 and Mid1 in early and late stages of cytokinesis.