Berlin 2008 – scientific programme

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BP: Fachverband Biologische Physik

BP 16: Pattern Formation and Developmental Processes

BP 16.6: Talk

Wednesday, February 27, 2008, 18:45–19:00, C 243

Spatiotemporal patterns in signal transduction: effect of cytoskeleton structure and molecular crowding — •Michael Klann, Alexei Lapin, and Matthias Reuss — Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany

Cellular signaling depends on the efficient translocation of signals from the cell membrane to target proteins. The cytoskeleton network hinders diffusion but also offers express-ways for active transportation along the filaments. Amplification or regulation of the signal strength through a cascade of reactions depends on the local concentration of the molecules, which is strongly affected by molecular crowding. The low number of molecules in signaling pathways leads to a significant level of stochastic noise. Local fluctuations that do not cancel out on the cell level due to nonlinear interactions lead to deviations from continuum ODE-models. To analyze the spatiotemporal signaling patterns affected by the inhomogeneous background of cellular architecture we developed a stochastic simulation method that allows us to track the position of every molecule of interest including reactions, diffusion and active transport through the cell. Simulations show that in presence of the cytoskeleton, diffusion is slowed down but the reaction rate is increased due to the higher effective concentration of reactants. Overall this can reduce the travel time from the plasma membrane to the nucleus. Active transport along the cytoskeleton furthermore increases the efficiency of the signaling cascade.