Imaging of Mobile Stable Nanoplatforms in the Live Cell Plasma Membrane

摘要: The plasma membrane has been hypothesized to contain nanoscopic lipid platforms, which are discussed in the context of “lipid rafts” or “membrane rafts”. Based on biochemical and cell biological studies, rafts believed play a crucial role many signaling processes. However, there is currently not much information their size, shape, stability, surface density, composition heterogeneity. We present here method allows for first time direct imaging stable platforms with raft-like properties diffusing live membrane. Our senses these by property assemble characteristic set fluorescent marker-proteins lipids time-scale seconds. A special photobleaching protocol was used reduce density labeled mobile down level well-isolated diffraction-limited spots, without altering single spot brightness. statistical distribution probe molecules per platform determined molecule brightness analysis. For demonstration, we consensus raft marker glycosylphosphatidylinositol-anchored monomeric GFP analogue Bodipy-GM1 preferentially partitions into liquid ordered phases. both markers found cholesterol-dependent homo-association living CHO Jurkat T cells resting state, thereby demonstrating existence small, mobile, containing probes. further applied technology address structural changes during fever-type heat shock: at elevated temperatures mGFP-GPI disappeared, accompanied an increase expression small shock protein Hsp27.