Viscous control of cellular respiration by membrane lipid composition

We describe a specific role for the viscosity of energy-transducing membranes in cellular respiration. Engineering of fatty acid biosynthesis in Escherichia coli allowed us to titrate inner membrane viscosity across a 10-fold range by controlling the abundance of unsaturated or branched lipids. These fluidizing lipids tightly controlled respiratory metabolism, an effect that can be explained with a quantitative model of the electron transport chain (ETC) that features diffusion-coupled reactions between enzymes and electron carriers (quinones). Lipid unsaturation also modulated mitochondrial respiration in engineered budding yeast strains. Thus, diffusion in the ETC may serve as an evolutionary constraint for lipid composition in respiratory membranes.

Source: ScienceNOW - December 6, 2018 Category: Science Authors: Budin, I., de Rond, T., Chen, Y., Chan, L. J. G., Petzold, C. J., Keasling, J. D. Tags: Biochemistry, Molecular Biology reports Source Type: news