Using Cell Surface Protein Distributions To Investigate The Physical Basis Of Plasma Membrane Lateral Heterogeneity

Abstract

It is widely recognized that proteins and lipids are heterogeneously distributed on the cell surface, yet little is known regarding the underlying physical principles that give rise to this membrane organization. Recently, we characterized robust and dynamic critical fluctuations in isolated plasma membrane vesicles and proposed that critical fluctuations provide a plausible physical basis for 50nm), consistent with previous studies. In addition, the detailed shapes of experimentally derived correlation functions provide additional information into the organizing principles that give rise to membrane heterogeneity. We evaluate the validity of different proposed mechanisms of membrane organization by fitting our experimental findings to predictions of various models. Models investigated include critical fluctuations, micro-emulsions, and membrane coupling to cytoskeletal components. Implications for cellular processes such as signaling will be discussed.1. Veatch, S. L., P. Cicuta, P. Sengupta, A. Honerkamp-Smith, D. Holowka, and B. Baird. 2008. Critical fluctuations in plasma membrane vesicles. ACS Chemical Biology 3:287-293.