Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
BP: Fachverband Biologische Physik
BP 9: Posters - Cell Mechanics
BP 9.6: Poster
Montag, 20. März 2017, 17:30–19:30, P3
A Protein Flux-based Mechanism for Midcell Sensing in Bacteria — •Silke Bergeler1, Dominik Schumacher2, Lotte Søgaard-Andersen2, and Erwin Frey1 — 1ASC for Theoretical Physics, Ludwig-Maximilians-Universität, München, Germany — 2Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
Precise positioning of the cell division site is essential for the correct separation of the genetic material into the two daughter cells. In myxobacteria, a protein cluster is formed on the nucleoid that performs a biased random walk to midcell and positively regulates cell division there. Deletion experiments show that PomZ, an ATPase, is necessary for this cluster movement. To investigate how the cluster is positioned at midcell, we introduce a mathematical model: ATP-bound PomZ dimers can attach to and quickly diffuse on the nucleoid. At the cluster, they can hydrolyze ATP and subsequently detach into the cytosol as ADP-bound monomers. It is known that this type of particle dynamics leads to different fluxes of PomZ into the cluster from both sides along the long cell axis, if the cluster is at an off-center position. We investigate this model both numerically, using stochastic simulations, and analytically, using reaction-diffusion equations. With our model, we are able to reproduce the movement of the cluster towards midcell. We perform parameter sweeps to test the robustness of the mechanism. Furthermore, we investigate the reaction-diffusion equations in a three-dimensional geometry mimicking the cell to study geometric effects. In summary, our study provides new mechanistic insights into self-organized intracellular positioning of protein clusters.