title: Nonequilibrium phase transitions in biomolecular signal transduction.
abstract: We study a mechanism for reliable switching in biomolecular signal-transduction cascades. Steady bistable states are created by system-size cooperative effects in populations of proteins, in spite of the fact that the phosphorylation-state transitions of any molecule, by means of which the switch is implemented, are highly stochastic. The emergence of switching is a nonequilibrium phase transition in an energetically driven, dissipative system described by a master equation. We use operator and functional integral methods from reaction-diffusion theory to solve for the phase structure, noise spectrum, and escape trajectories and first-passage times of a class of minimal models of switches, showing how all critical properties for switch behavior can be computed within a unified framework.
authors.affiliation: Santa Fe Institute, Santa Fe, New Mexico 87501, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Smith
authors.forename: Supriya
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Walter
authors.initials: W
authors.lastname: Fontana
authors.forename: David
authors.initials: D
authors.lastname: Krakauer
mesh_terms: D004058:Diffusion; D008954:Models, Biological; D044367:Phase Transition; D015398:Signal Transduction; D013269:Stochastic Processes; D013997:Time Factors