MECHANICAL COMMUNICATION BETWEEN MICROTUBULE MOTORS

BENSEÑOR, LORENA; RODRIGUEZ, DANIELA; LEVI, VALERIA; WETZLER, DIANA E..; SUED, MARIELA; BRUNO, LUCIANA; DE ROSSI, MARÍA CECILIA; DE ROSSI, MARÍA EMILIA; GELFAND, VLADIMIR

Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

SOCIEDADES DE BIOCIENCIAS ARGENTINAS

Molecular motors transport a widevariety of cellular cargoes positioning them in the cytoplasm with highspatial?temporal precision.In particular,microtubule-dependent-motors, dynein and kinesin, drive organellesbi-directionally; dynein transports cargoes toward the minus end of themicrotubule whereas kinesin moves in the opposed direction. Therefore, theseopposed-polarity motors compete with each other to determine the finaldirection of motion. In this work, we explore the interplay of the opposedpolarity motors kinesin-1 and cytoplasmic dynein during peroxisome transportalong microtubules in Drosophila S2 cells. Usingsingle particle tracking, we registered fluorescent peroxisomes trajectorieswith nanometer accuracy and millisecond time resolution to extract quantitativeinformation on the bidirectional motion of organelles. We computed thedistributions of run length and speeds. These last data were statisticallyanalyzed with a Gaussian functions mixture model following the Akaikeinformation criterion. Transport performance was studied in cells expressing aslow chimeric plus-end directed motor or the kinesin heavy chain. We alsoanalyzed the influence of peroxisomes membrane fluidity in methyl-βciclodextrin treated cells. The experimental data was confronted with numericalsimulations of two well-established tug of war scenarios. Our results supportthe existence of a crosstalk between opposed-polarity motor teams. Moreover,the slowest teams seem to mechanically communicate with each other through themembrane to trigger transport.Keywords: single particle tracking, molecular motors,intracellularTransport