Extracting Landscape Features from Single Particle Trajectories.

The predictive power of dynamical models of cell signaling is often limited due to the difficulty in estimating the relevant kinetic parameters. Super-resolution microscopy techniques can provide in vivo trajectories of individual receptors, and serve as a direct source of quantitative information on molecular processes. Single particle tracking (SPT) has been used to extract reaction kinetic parameters such as dimer lifetimes and diffusion rates. However, signaling models aim to characterize kinetics relevant to the entire cell while SPT follows individual molecules in a small fraction of the cell. The gap in resolution can be bridged with spatial simulations of molecular movement, validated at SPT resolution, which are used to infer effective kinetics on larger spatial scales.