Regensburg 2010 – scientific programme

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BP: Fachverband Biologische Physik

BP 36: Posters: Tissue Dynamics, Charge Effects, and Anomalous Transport

BP 36.10: Poster

Thursday, March 25, 2010, 17:15–20:00, Poster B2

Anomalous transport in living cells — •Doris Heinrich — Biophysics of Cell Dynamics Group, Fakultät für Physik und CeNS, LMU München, Germany

Living cells exhibit exceptional dynamic properties, caused by the presence of ATP-driven motion. In particular, intracellular transport of cargos proceeds by successive phases of diffusion and active movement along microtubules via dynein and kinesin motors. While passive Brownian motion allows for intracellular transport of molecules on the nanoscale, it becomes inefficient for transport of large proteins, vesicles and organelles on the scale of a whole cell. We developed an automated and reliable time-resolved identification method for motility state signatures of cytoplasmic tracers. Such an approach is both experimentally challenging and of fundamental importance for our understanding of intracellular transport processes. We investigated the motion of micron- and nanosized particles in the amoeba Dictyostelium discoideum (Dd). The distribution of active transport durations is found to decay exponentially with a characteristic time t = 0.65 s. The velocity distribution of active events exhibits several peaks, revealing the signature of a finite number of molecular motors working collectively. By further applying spatially and temporally defined external boundary conditions to these cells, like drugs, precisely monitored magnetic field gradients or by cell motility essays on pre-ordered 3D topologies, we induce changes in cellular function.