2010-11-03
10:15 at HCI J 574

Self-organization of active polar gels and cell motility

Karsten Kruse

Theoretische Physik - Universität des Saarlandes, Saarbrücken

Many movements of eukaryotic cells are driven by the cytoskeleton. This cellular structure plays essential roles in various vital processes like cell division, cell locomotion, or the internal organization of subcellular components. From a physical point of view it is an active polar gel that consists of filamentous proteins, notably microtubules and actin filaments, which are structurally polar. Activity in the system results from processes driven by the hydrolysis of ATP, like filament assembly and disassembly or the action of motor proteins. While a lot is now known about the biochemistry of individual cytoskeletal proteins, we still lack a thorough understanding of how these components are organized on a cellular scale. In this talk, physical descriptions of cytoskeletal dynamics will be discussed. The central finding is that collective effects emerging from interactions between a few key cytoskeletal components can lead to spatio-temporal structures similar to those observed in cells. Specifically, I will first discuss the cytoskeleton-dependent organization of pigments in cells that allow fish to change color. Secondly, I will address the role played by self-organized polymerization waves for orchestrating cytoskeletal constituents in crawling neutrophils and amoeba.