CAPTURING THE PHYSICS OF LIFE ON 3D-TRAFFICKING SUBCELLULAR NANOSYSTEMS

ongoing

Which physical principles govern life regulation at the level of subcellular, membrane-enclosed nanosystems, such as transport vesicles and organelles? How do they achieve controlled movements across the crowded intracellular world? Which is the structural and functional organization of their surface and their lumen? This is only a small subset of key open questions that the biophysical approach envisaged here will allow to answer directly within living matter, for the first time. Thus far, state-of-the-art optical microscopy tools for delivering quantitative information in living matter failed to subtract the natural 3D movement of subcellular nanosystems while preserving the spatial and temporal resolution required to probe their structure and function at the molecular level. CAPTUR3D will tackle this bottleneck. An excitation light-beam will be focused in a periodic orbit around the nanosystem of interest and used to localize its position with unprecedented spatial (~10 nm) and temporal (~1000 Hz frequency response) resolution. Such privileged observation point will push biophysical investigations to a new level. For the first time, state-of-the-art imaging technologies and analytical tools (e.g. fluorescence correlation spectroscopy), will be used to perform molecular investigations on a moving, nanoscopic reference system. The insulin secretory granule (ISG) is selected as a paradigmatic case study. Key open issues at the ISG level are selected, namely: (i) ISG-environment interactions and their role in directing ISG trafficking, (ii) ISG-membrane spatiotemporal organization, (iii) ISG-lumen structural and functional organization, (iv) ISG alterations in type-2 diabetes (T2D). These issues will be tackled directly within human-derived Langherans islets. CAPTUR3D is envisioned not only to foster our knowledge on T2D physiopathology but also to concomitantly drive an unprecedented revolution in the way we address living matter at the subcellular scale.