Our bodies rely on the precise shaping and remodeling of cell membranes to perform fundamental biological processes such as fertilization and cell-cell communication. These shape changes are actively regulated by membrane-associated proteins, yet the physical principles underlying their function remain poorly understood. Uncovering these mechanisms is not only essential for advancing our basic understanding of biology, but also for enabling targeted therapeutic interventions in processes ranging from reproduction to viral infection.
Among the most intriguing membrane-associated proteins are tetraspanins (TSPANs)—a family of four-pass transmembrane proteins found in nearly all cell types. TSPANs have been implicated in a wide range of physiological and pathological processes, including cell-cell fusion, viral entry, immune signaling, and the formation of newly discovered organelles called migrasomes, which mediate intercellular communication. Despite their biological importance, the ways in which TSPANs exert their function—particularly how their localization and activity are influenced by physical membrane properties like curvature and tension—are still largely unknown.
This project aims to fill this critical gap by applying cutting-edge biophysical tools to directly test how TSPANs respond to and modulate membrane mechanics. Specifically, we will combine optical tweezers, micropipette aspiration, confocal microscopy, and atomic force microscopy (AFM) to develop quantitative, high-resolution assays that reconstitute key TSPAN-mediated events from the bottom up. This approach will allow us to isolate and characterize the individual roles of membrane tension and curvature in TSPAN function.
Our objectives are threefold:
1. To reveal the effect of membrane tension on the formation of TSPN domains, using a novel AFM-based assay.
2. To explain the mechanism by which TSPNs drive migrasome formation, a new mode of cell-cell communication.
3. To characterize how TSPNs mediate membrane fusion, with applications to both fertilization and viral entry.
By tackling these aims, the project will generate transformative insights into how membrane mechanics shape biological function, revealing new paradigms for membrane remodeling in health and disease. The findings have the potential to impact several fields simultaneously: from reproductive biology (e.g. through the development of novel contraceptives and infertility treatments), to virology (e.g. new targets for antiviral therapies), to membrane biophysics. Furthermore, the fundamental principles uncovered here may apply to a broad range of processes in which tetraspanins are implicated, including cancer metastasis and immune cell activation.
