Calendar Details

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Tuesday, January 29

Biomembrane Physics of Cellular Signaling

Georg Pabst, Institute of Molecular Biosciences, Biophysics Division, University of Graz, Graz, Austria
Joint Institute for Neutron Sciences Seminar
2:30 PM — 3:30 PM, Building 8630 (JINS), Room A-202
Contact: Hope Moore-Webb (hmoore2@utk.edu), 865.576.8630

Abstract

Cells – central building blocks of life – communicate among each other or with their internal organelles via complex pathways. The plasma membrane with a functional layer composed of lipids and proteins plays a central role in these processes allowing for selective transport of materials and signal transduction, respectively. When considering specific function, the focus typically is on proteins. However, driven either by the membrane raft hypothesis and/or by observations on lipid homeostasis under (patho)physiological conditions, the functional role of membrane lipids has become more and more apparent of late. We seek to understand the physics pertaining to the specific coupling of membrane lipids and proteins using well-defined lipid mixtures that mimic the plasma membrane and simple protein models. In particular, we focused on determining membrane structural and elastic parameters (membrane thickness, bending rigidity, spontaneous curvature, Gaussian curvature modulus) allowing us to predict, for example the ratio of open to closed states of ion-channels or the partitioning of transmembrane proteins into a given lipid environment. In this framework I will discuss our recent findings on the elasticity of liquid ordered/liquid disordered domains and effects due to the interplay of cholesterol and ceramide.