William Bement

Self-organization in cell division and cell repair

Our lab studies two fundamental cellular processes: cytokinesis and cell repair. Each of these processes are outwardly quite complex. Cytokinesis, for example, results from the combined action of the actin filament and microtubule cytoskeletons, and the participation of hundreds of different proteins that regulate the actin filament and microtubule cytoskeletons. Cell repair results from the calcium-dependent aggregation and fusion of membranous compartments at the cell wound site, which is somehow coordinated with and followed by an actin filament-based response that repairs the damaged cytoskeleton of the cell cortex. Again, hundreds of different proteins are involved. In spite of their apparent complexity, work from our lab suggests that both cytokinesis and cell repair are underpinned by self-organization. In particular, the Rho GTPases–Rho, Rac, and Cdc42–seem to direct the processes of cytokinesis and cell repair by virtue of their ability to form self-organized cortical waves (Figure 1). Much of our current effort is focused on understanding how these waves form and how they convey information needed for cytokinesis and repair. In addition, we are using synthetic biology approaches to generate novel, self-organized wave patterns both to better our understanding of how Rho GTPase waves work and to endow cells with new capacities.