One of the most important, yet unresolved questions in cell biology research is how specific membrane compositions of organelles and the plasma membrane composition are maintained despite the vigorous trafficking of membrane components. Closely coupled to this question is how membrane components are distributed between differing membrane trafficking pathways or selectively retained in organelles involved in membrane trafficking. An important, yet controversy hypothesis is that biological membranes segregate into domains of differing composition that act as membrane signaling platforms and are involved in membrane component sorting and trafficking.
In part due to the overwhelming complexity of biological membranes, lipid model membrane systems have been extensively used for characterizing the phase behavior of lipid mixtures. This talk demonstrates how lipid membrane composition gradients can couple to curvature gradients in both biological and model membranes. This composition / curvature coupling may be involved in membrane sorting and trafficking events in cellular sorting stations such as the trans-Golgi network, the endocytic recycling compartment as well as the plasma membrane.