Events at Physics |
Events on Tuesday, September 16th, 2014
- Chaos & Complex Systems Seminar
- Cyclin-dependent kinase-confined cortical chaos
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin Hall (Refreshments will be served)
- Speaker: Bill Bement, UW Department of Zoology
- Abstract: Cytokinesis--the final step in cell division--is restricted to a discrete point in the cell division cycle referred to as "C-phase". In C-phase, the cortex of the cell is uniquely competent to respond to signals from the spindle by assembling the cytokinetic apparatus. C-phase follows anaphase onset and varies in length according to cell type. We have discovered that anaphase onset in frog and echinoderm embryos is associated with cortical excitability, manifest as waves of Rho activity and F-actin that traverse the underside of the plasma membrane. The waves are suppressed by cyclin dependent kinase 1 (Cdk1) and can be driven into a chaotic form when Cdk1 activity is experimentally suppressed. Remarkably, the excitability entails F-actin mediated Rho inhibition. We propose that C-phase is explained by the development of cortical excitability which is normally restricted to a discrete portion of the cell cycle Cdk1 and that excitability provides the cell with the means to balance the conflicting needs of speed, precision and flexibility during cell fission.
- Host: Clint Sprott