BPS2026 – Structural adaptation of lipids to support dynamic membrane function and life at extremes

Lipid membranes are essential to every cell. Though they are acutely sensitive to temperature, pressure, and aqueous chemistry, membranes have evolved to remain stable, fluid and morphologically dynamic in various, often extreme, environments. The established principle of homeoviscosity describes how organisms adjust lipid chain saturation and length to control lateral mobility (fluidity) of membrane components. Recent work has uncovered a complementary principle, homeocurvature, whereby the headgroup-to-tail profile (intrinsic curvature) of lipids adapts to promote elastic stress within membranes. Homeocurvature was first demonstrated as an adaptation to deep-sea pressure and is presented in this context across diverse marine taxa. It also occurs in common yeasts and human cells, implying that control of lipid shape is widespread. Ether lipids such as plasmalogens contribute to both deep-sea and lab-induced pressure responses, motivating a mechanistic investigation of ether lipids’ capacity to destabilize bilayers. Experiments and simulations indicate that ether-linked glycerol backbones have a consistent effect on lipid intrinsic curvature and phase behavior and represent a discrete module of phospholipid structure alongside headgroups and radyl chains. Implications of the presented results range from the effects of global change on marine life to dynamic membrane processes such as neurotransmission and related pathologies like Alzheimer’s disease.