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BP: Fachverband Biologische Physik
BP 11: Poster A: Single Molecule, Multicellular, Bioimaging, Focus Sessions, etc.
BP 11.26: Poster
Monday, March 22, 2021, 16:30–19:00, BPp
Optogenetic control of intracellular flows and cell migration: a minimal active gel model — •Oliver M. Drozdowski1,2, Falko Ziebert1,2, and Ulrich S. Schwarz1,2 — 1Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120 Heidelberg, Germany — 2BioQuant, Heidelberg University, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
The actin cytoskeleton of cells is in continuous motion due to both polymerization of new filaments and their contraction by myosin II molecular motors. Through adhesion to the substrate, such intracellular flow can be converted into cell migration. Recently, optogenetics has emerged as a new powerful experimental method to control both actin polymerization and myosin II contraction. While optogenetic control of polymerization can initiate cell migration by effecting protrusions, it is less clear if and how optogenetic control of contraction can effect cell migration. Here we analyze the latter situation using a minimal variant of active gel theory into which we include optogenetic activation as a spatiotemporally constrained perturbation. The model can describe the symmetrical flow of the actomyosin system observed in optogenetic experiments but not the long-lasting polarization required for cell migration. Motile solutions become possible if cytoskeletal polymerization is added to the boundary conditions. Optogenetic activation of contraction can then initiate locomotion in a symmetrically spreading cell and strengthen motility in an asymmetrically polymerizing one. If designed appropriately, it can also arrest motility even for protrusive boundaries.