Abstract

Lateral Organization Of Plasma Membrane Constituents At The Nanoscale

Gerhard Schutz, Professor, Vienna University of Technology

The organization and dynamics of proteins and lipids in the plasma membrane, and their role in membrane functionality, have been subject of a long-lasting debate. Particularly, it is of interest how proteins are spatially distributed over the membrane, and whether they conjoin and move as part of multi-molecular complexes. In my lecture, I will provide examples for both topics: Superresolution microscopy was used to resolve the spatial distribution of mitochondrial membrane proteins. We found preferential localization of UCP4 and the F0F1 ATP synthase in different sub-compartments of the inner mitochondrial membrane. In addition, I will discuss potential artifacts in PALM or STORM-based superresolution microscopy, and a workaround using a label-titration approach. We developed a special method termed TOCCSL, which allows for determining molecular associations of diffusing membrane proteins based on single molecule brightness or co-diffusion analysis. By this method, we found the homo-dimerization of GPI-anchored proteins in the live cell plasma membrane, and we determined the subunit stoichiometry of an ion channel and a neurotransmitter transporter.