Regensburg 2019 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 60: Statistical Physics in Biological Systems III

DY 60.2: Vortrag

Freitag, 5. April 2019, 10:15–10:30, H3

GTPase cascades can perform as both robust switches and biochemical oscillators — •Andreas Ehrmann, Basile Nguyen, and Udo Seifert — II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany

GTPases regulate a wide range of cellular processes, such as intracellular vesicular transport, signal transduction, and protein translation. These hydrolase enzymes operate as biochemical switches by toggling between an active guanosine triphosphate (GTP)-bound state and an inactive guanosine diphosphate (GDP)-bound state. We compare two switch models, a single-species switch and an interlinked switch that consists of two species coupled through positive and negative feedback loops. We find that interlinked switches are closer to the ideal all-or-none switch and are more robust against input fluctuations. While the single-species switch can only achieve bistability, interlinked switches can be converted into oscillators by tuning the cofactor concentrations. These regimes can only be achieved with sufficient chemical driving, which is associated with GTP hydrolysis. In this study, we provide a minimal thermodynamically consistent model that can achieve bistability and oscillations with the same feedback structure.