Non-equilibrium Collective Transport on and off Molecular Highways
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)Abstract
Intracellular motion of motor proteins on cytoskeletal filaments provides interesting examples of non-equilibrium transport phenomena.
The stochastic stepping of a collection of motors along one or more filaments, with motor exchange between filament and cytoplasm, can be mapped in a three-dimensional lattice gas model of hard spheres, generalization of a totally asymmetric simple exclusion process with non conserved dynamics (TASEP coupled with Langmuir Kinetics). The non-equilibrium one-dimensional directed motion of particles along the filament(s) is then coupled with the three-dimensional diffusive motion of particles in the surrounding environment.
I will focus on new physical properties emerging from such a model, in particular those peculiar to its three-dimensional nature and the absence of particle reservoirs in the system.
These properties concern traffic jam and phase separation phenomena for typical parameters of motor proteins and have interesting biological implications for transport processes in the cell.