Analysis of persistence during intracellular actin-based transport mediated by molecular motors,

C. PALLAVICINI; M. DESPÓSITO; V. LEVI; L. BRUNO

JOURNAL OF PHYSICS: CONFERENCE SERIES

IOP

Año: 2010 vol. 246 p. 1 - 5

1742-6588

The displacement of particles or probes in the cell cytoplasm as a function of time is characterized by different anomalous diffusion regimes. The transport of large cargoes, such as organelles, vesicles or large proteins, involves the action of ATP-consuming molecular motors. We investigate the motion of pigment organelles driven by myosin-V motors in extit{Xenopus laevis} melanocytes using a high spatio-temporal resolution tracking technique.By analyzing the turning angles ($phi$) of the obtained 2D trajectories as a function of the time lag, we determine the critical time of the transition between anticorrelated and directed motion as the time when the turning angles begin to concentrate around $phi=0$. We relate this transition with the crossover from subdiffusive to superdiffusive behavior observed in a previous work cite{Bru}. We also assayed the properties of the trajectories in cells with inhibited myosin activity, and we can compare the results in the presence and absence of active motors.