Theory Lunch this week

What cell shape oscillations tell us about cortical actin-microtubule interactions and amoeboid migration

Friday, 19 Oct 2012, 12:00-1:30 pm, Warren Alpert 563, HMS

Kenneth Jacobson
Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill

Abstract
Many cellular responses to environmental stimuli involve large-scale changes in cell morphology. For example signaling molecules, such as hormones or growth factors, can induce cell differentiation, proliferation, or migration. These global changes in cell shape are highly coordinated and require dynamic regulation of the actin cytoskeleton. Therefore understanding how the actin and microtubule cytoskeleton and associated regulatory proteins function as an integrated system is a central challenge for cell biology. The morphological oscillations that occur during cell spreading are ideally suited for performing a systems-level investigation into the biochemical and biomechanical mechanisms that drive changes in cell shape. In the broader context, these oscillations constitute a mechanochemical prototype of how signaling networks regulate cytoskeletally driven mechanical behavior that in turn feeds back to modulate the signaling network. Importantly, fluorescently labeled cytoskeletal proteins and fluorescent biosensors allow dynamic structural features of the actin-based cortex and spatiotemporal activity of signaling molecules and visualized. I will discuss what we know about the dynamic structural changes in the actin cortex during oscillations, how Rho proteins regulate these oscillations, how this model may be related to amoeboid migration and emerging theoretical models for this phenotype. If time permits, I will also discuss a new paradigm for membrane domains based on pathogen receptors located on the surface of dendritic cells.

TL schedule here.