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Résumé |
The ability to reshape the plasma membrane is essential for cells’ life. To
perform membrane reshaping, cells rely on a precise controlled coupling of the
plasma membrane and the actin cytoskeleton, which can apply physical forces to the
membrane while being mechanically linked to it. A prominent example is filopodia,
finger-like and actin-rich membrane protrusions important for numerous cellular
processes including cell morphogenesis and cancer invasion. Yet, it remains poorly
understood how cells control when and where to trigger actin assembly on the
plasma membrane to initiate filopodia. Notably, membrane curvature sensor protein
IRSp53 has been identified as a key player in filopodia formation. However, the
precise mechanism of IRSp53-driven filopodia formation remains elusive. To address
this fundamental question in cell biology, we performed experiments using in vitro
reconstitution systems composed of model membranes and purified proteins,
including IRSp53, actin and actin regulatory proteins. In this seminar, I will
present our results demonstrating how IRSp53 initiates actin-filled membrane
protrusions and facilitates their stabilization. |
