Energetics and irreversibility of Rho-GTP protein patterns on the membrane of starfish oocytes

Cellular protein patterns emerge from a combination of protein interactions, transport, and chemical reactions at the molecular level, and are key to information transmission during cellular processes. While pattern formation is considered a dynamical phase transition, protein patterns are inherently out of equilibrium, and a continuous influx of chemicals and energy are required to create and maintain these dissipative structures. What is the work needed to create and maintain a pattern, and what is the efficiency with which information exchanges through these patterns? Here we use chaotic dynamics of Rho-GTP patterns on the membrane of starfish oocytes as a model system to answer these crucial thermodynamic questions. We perform biochemical and metabolic perturbations to tune spatiotemporal oscillations of the patterns, and use information theory metrics, such as irreversibility, to quantify lower bounds of energy dissipation in the system. This approach provides a better understanding of the chaotic and nonequilibrium dynamics of Rho-GTP spatiotemporal patterns.