Physiology/PMI Seminar

**Thursday** December 12th @ 3:00pm

*Refreshments @ 2:45pm

Location: Clinical Research Building (CRB), Austrian Auditorium, 1st Floor

Speaker: Alexandra Colin, Ph.D., CNRS Researcher, National Centre for Scientific Research (CNRS), France

TITLE: “Dynamic and scaling of competitive actin architectures"

Understanding how cells adjust the size of their dynamic actin architectures in relation to overall cell size is a fundamental question. Due to their complexity, the relationship between the self-assembling properties of actin architectures and their ability to scale with cell size remains poorly understood. Decoupling these parameters to assess their relative contributions in a cellular context is extremely challenging, so we have developed a bottom-up approach to identify the key molecular mechanisms involved in the scaling of dynamic actin architectures. We developed an experimental system in which polystyrene beads are propelled by an actin comet in a cell-sized microwell containing a limited amount of components. We have established the biochemical conditions to ensure bead movement over several tens of hours. Subsequently, we studied how compartment size, biochemical conditions and number of beads in competition affect comet size and bead velocity at steady state. Thanks to this reductionist approach, we were able to establish some general principles controlling the scaling of actin architectures.