Friday, May 08, 20152:00 PM - 3:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Stochastic transitions in a prototype bistable system of kinase--phosphatase interactions on the plasma membran
Marek KochanczykPolish Academy of Sciences
For finite diffusion, behavior of the spatially extended, bistable system differs qualitatively from the behavior of the same system in the well-mixed regime: Even when a small isolated subdomain remains mostly inactive, the chemical traveling wave may propagate, leading to the persistent activation of a larger domain. The activating wave can be induced after a small subdomain is activated as a result of a stochastic fluctuation; for the considered system, such spontaneous onset of activity is radically more probable in subdomains characterized by slower diffusion. The steady state dependence on the diffusivity and size of the reactor, observed within microscopic kinetic Monte Carlo simulations on the 2-D lattice for the spatially extended system, will be explained on the basis of analytical considerations of a simpler bistable system, evolution of which is equivalent to a one-dimensional birth-and-death process.
Host: Bill Hlavacek