Influence of the biophysical properties of molecular motors on intracellular transport

M. C. DE ROSSI; LUCIANA BRUNO; DIANA E. WETZLER; MARIELA SUED; RODRIGUEZ D; VALERIA LEVI

Sierra de la Ventana

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofísica

Bidirectional transport along microtubules is driven by kinesin and dynein motors, which transport cargoes toward the plus and minus end of microtubule, respectively. The overall direction of motion results from the cooperation and/or competition between these opposed-polarity motors. In this work, we explore how the biophysical properties of motors affect the dynamics of fluorescent peroxisomes in D. melanogatser s2 cells to get insight into the mechanisms involved in the bidirectional transport of organelles.Using single particle tracking, we registered trajectories of peroxisomes and determined the run length and velocity distributions to get information about the mechanism of transport and the population of motors involved. We compared the transport properties in wild type cells with those obtained for cells expressing the slow kinesin Eg5. While the run lengths and velocities of minus end directed peroxisomes are not affected by the presence of Eg5,both run lengths and velocities of plus end directed peroxisomes decreased. Our results suggest that Eg5 acts as an anchor to kinesin 1, reducing the forward stepping frequency and increasing the probability of detachment.