title: Impact of external stimuli and cell micro-architecture on intracellular transport states.
abstract: A living cell is a complex out-of-equilibrium system, in which a great variety of biochemical and physical processes have to be coordinated to ensure viability. We investigate properties of intracellular transport in single cells of the amoeba Dictyostelium discoideum, a relevant model organism due to its cytoskeleton simplicity. In the cells, vesicles undergo two types of motion: directed transport, driven by molecular motors on filaments, or thermal diffusion in a crowded active medium. We present results obtained with our recently developed TRAnSpORT algorithm, which performs a high-resolution temporal analysis of the track of endosomal superparamagnetic particles and splits intracellular transport into different motion states. It results in a two-state model, distinguishing active and passive transport phenomena. We can extract the precise effect of cellular micro- and nanoarchitecture on endosomal transport by disturbing the cytoskeleton through the use of depolymerizing drugs (Benomyl for microtubules, and Latrunculin A for F-actin). Further, we investigate how cytoskeleton filaments act together in order to maintain cell integrity, by applying external mechanical force on the magnetic particle and influencing its motion.
authors.affiliation: Fakultät für Physik, Ludwig-Maximilians Universität and Center for NanoSciences, Geschwister-Scholl-Platz 1, 80539 München, Germany.
authors.forename: Jean
authors.initials: J
authors.lastname: Mahowald
authors.forename: Delphine
authors.initials: D
authors.lastname: Arcizet
authors.forename: Doris
authors.initials: D
authors.lastname: Heinrich
mesh_terms: D000199:Actins / Q000737:chemistry / Q000378:metabolism; D000465:Algorithms; D000818:Animals; D001542:Benomyl / Q000494:pharmacology; D001693:Biological Transport, Active; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D003599:Cytoskeleton; D004023:Dictyostelium / Q000737:chemistry* / Q000378:metabolism; D008280:Magnetics; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism; D053778:Thiazolidines / Q000494:pharmacology
chemical_list: D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D053778:Thiazolidines; C037067:latrunculin A; D001542:Benomyl