Trajectory analysis of organelles transported by molecular motors within living cells

DE ROSSI, MARÍA CECILIA; DE ROSSI, MARÍA EMILIA; LEVI, VALERIA; BRUNO, LUCIANA

Workshop; Workshop Statistical Physics in Biological Networks; 2020

Intracellular transport relies on molecular motors that step along cytoskeletal filaments actively dragging cargoes through the crowded cytoplasm. Particularly, microtubule-dependent transport is driven by dynein and kinesin motors which move cargoes toward the minus and plus end of these filaments and define bidirectional trajectories with frequent switches in direction. In this work, we used a fast and precise single particle tracking method (SPT) to follow the motion of individualorganelles within living cells and analyzed their trajectories to obtain information regarding the relation between organelle dynamics and the biophysical properties of motors. We developed a set of numerical algorithms programmed in IDL (Interactive Data Language) to simultaneously and efficiently process a large number of trajectories. The routines allowed us to identify unidirectional and uninterrupted processive tracks (runs), pauses and changes in the direction of motion (reversions) in each trajectory and further compute different parameters associated with organelle transport.