Trajectories analysis of organelles transported by molecular motors within living cells

DE ROSSI M.C.; BRUNO L; LEVI V; DE ROSSI ME

Puerto Madryn, Chubut

Congreso; Statistical Physics in Biological Networks.; 2020

INFERNET, Universidad de Gral. Sarmiento

Transport of vesicles, organelles and other cellular cargoes is central to a wide variety of biological processes. 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 to follow the motion of individual organelles 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: run length, local and mean speed and the mean square displacement. The data obtained from the quantitative analysis of trajectories were used to explain how microtubule motors work together during organelle transport.