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

CARLA PALLAVICINI; MARCELO A. DESPÓSITO; VALERIA LEVI; LUCIANA BRUNO

Journal of Physics Conference Series (LAWNP'09)

IOPscience

Año: 2010 p. 12038 - 12042

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 Xenopus laevis melanocytes using a high spatio-temporal resolution tracking technique. By analyzing the turning angles of the obtained 2D tra jectories 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 fi = 0. We relate this transition with the crossover from subdiffusive to superdiffusive behavior observed in a previous work [5]. We also assayed the properties of the tra jectories in cells with inhibited myosin activity, and we can compare the results in the presence and absence of active motors.