Concentration profiles of F-actin binding molecules shape the dynamics of actin driven motility
Prof. Martin Falcke (Humboldt University)
Thursday 12th November, 2015 14:00-15:00 Maths 522
Actin-based motility in reconstituted systems and cells is driven by polymerization at a surface to which nucleation/polymerization promoting factors are attached. Polymerization generates new free binding sites for F-actin binding molecules close to that surface leading to a constant flux of free molecules towards that volume range and of F-actin bound molecules away from it. Free F-actin binding molecule concentration is lower or even depleted close to the surface than in the bulk, if the flux towards the surface is diffusion flux. We analyze the conditions for depletion and its consequences for F-actin network structure and dynamics. A gradient in mechanical properties of the network due to concentration gradients of myosin and cross-linkers causes a rich variety of dynamics observed in cells and reconstituted systems.