eTANGO was awarded the BIST Ignite Grant in April, 2017. The news release can be found here.
eTANGO will employ a multidisciplinary approach that combines state-of-the-art genetic manipulations of the protein TANGO1 and its binding partners together with advanced optical techniques and biophysical modeling to monitor the organization and dynamics of collagen export from the endoplasmic reticulum (ER). By merging the know-how of the collaboration, eTANGO will be able to provide for the first time a quantitative description of the spatiotemporal events that lead to collagen export from the ER.
Multidisciplinarity within eTANGO
eTANGO is truly a multidisciplinary project that aims to provide quantitative molecular and physical understanding of a process of fundamental and translation importance, i.e., collagen export. This is uniquely achieved by establishing collaboration between experts in molecular & cell biology at CRG (Malhotra’s lab) and physicists & biophysicists at ICFO (Garcia-Parajo’s lab). eTANGO merges multidisciplinary elements that include (i) molecular biology tools; (ii) advanced microscopy techniques and quantitative data and image analysis to visualize the structure and dynamics of membranes and proteins with unprecedented spatial and temporal resolution; and (iii) theoretical membrane biophysics to identify different forces that remodel membrane shape during the formation of the collagen-containing carriers.
Progress: updated abstract as of December 2017
Over the past four decades, we have witnessed the discovery of the molecular machinery for protein secretion. It is now known how cells secrete proteins, including insulin, neurotransmitters, hormones and growth factors. However, these discoveries do not reveal how cells secrete bulky cargos such as collagens, which constitute up to 25% of our dry body weight and are necessary for tissue organization, skin formation, and bone mineralization. Collagens are large, rigid proteins that cannot be accommodated into COPII vesicles, the canonical (small) transport carriers that export most secretory proteins from the endoplasmic reticulum (ER). How are then collagens secreted? TANGO1, an ER-resident transmembrane protein, was found to be required for collagen export. TANGO1 coordinately selects, partitions, and organizes folded collagen, COPII export machinery, and membrane acquisition to generate a transport carrier commensurate with the size of collagens. eTANGO aims at unraveling the molecular and physical mechanisms by which TANGO1 exports large cargos, such as collagens, from the ER. Expanding on the successful results obtained during the seeding phase, we will employ a multidisciplinary approach that combines state-of-the-art genetic manipulations with advanced optical techniques and biophysical modeling to investigate the organization and dynamics of TANGO1-mediated collagen export from the ER. Specifically, we will a) resolve the stoichiometry and 3D-molecular architecture of collagen export domains by multicolor 3D-STORM and single molecule step photobleaching; b) determine the dynamics of collagen export from the ER by means of multicolor live cell STED microscopy and intracellular single particle tracking; and c) develop and analyze a quantitative model for TANGO1-dependent formation of collagen-containing transport carriers. These groundbreaking approaches will provide a comprehensive quantitative molecular and mechanical understanding of how collagens are exported from the ER. These findings will also allow us, in the future, to design chemicals to control collagen homeostasis and thus a means to alleviate human pathologies such as tissue fibrosis and bone mineralization defects.