Filopodia tip: chemical and mechanical sensors
Filopodia are thin and dynamic tubular plasma membrane protrusions, which can sense the cells’ surroundings and exert forces on solid substrates or ECM. Their retraction is induced by adhesion to their tip, in particular by attaching solid beads; in contrast, counteracting mechanical forces can stall or even invert filopodia retraction. I will summarize our work aiming at characterizing the chemical and mechanical sensitivity of filopodia tips with optical tweezers. Globally, our measurements show that the tip region and its adhesion to external media determine filopodia dynamics, allowing tip bound filopodia to continuously probe its surroundings in a load-and-fail manner. Eventually, I will introduce open questions that could be addressed in the coming years on the tight coupling between filopodia adhesion to ECM and filopodia mechanical properties.
Bio
Patricia Bassereau is currently CNRS Directrice de Recherche (equivalent to professor) at the Institut Curie in Paris where she is the leader of the group “Membranes and cellular functions”. She started her carrier in Soft matter. She got her CNRS position in 1986. She worked seven years in Montpellier (GDPC) on the structure of self-assembled surfactant-based systems and one year as a visiting scientist at the IBM Almaden Center (San Jose, USA) on the structure of thin films of polymers. In 1993, she came to the Institut Curie. She first studied the interactions of soluble proteins with polymer monolayers, but soon after started to address questions related to “Physics of the cell.” She develops a multidisciplinary approach, largely based on synthetic biology and on the development and study of biomimetic systems, as well as quantitative mechanical and microscopy methods to understand the role of biological membranes in important cellular functions such as intracellular trafficking, endo/exocytosis, transmembrane transport of ions (“active membranes”), protein diffusion or cell adhesion. Additionnally, she studies the mechanics of single filopodia in living cells, and in parralel in vitro the generation of cell protrusions.
Web site: http://umr168.curie.fr/en/Bassereau-group