Single Molecule Studies of Tau Protein in the Abel Trap

Abstract

Neuronal mRNA trajectories exhibit a diverse range of behaviors along tracks including cytosolic diffusion and retrograde/anterograde transport. From our analysis, we obtain detailed distributions of transport rates and diffusivities along individual mRNA trajectories, as well as the lifetimes of each state of motion. We find that the rate of anterograde transport is greater than that of retrograde transport, indicating a possible role of forwards-backwards transport of the mRNA particles in distributing these molecules throughout the cell. To illustrate the broad applicability of our approach, we also use it to classify the heterogeneous oscillatory motion of sister kinetochores during HeLa cell division. While our results are consistent with sliding window averages commonly employed to analyze kinetochore dynamics, the Bayesian HMM infers local switching and pausing dynamics that are uniquely resolved by singleparticle-based analysis.