Measuring forces at the molecular scale in live cells
Forces exerted at the molecular level are central to countless processes in health and disease. However, directly measuring molecular forces in vivo remains difficult if not impossible using existing approaches. During clathrin-mediated endocytosis (CME) in yeast, the plasma membrane is deformed into a vesicle by the forces produced by the actin cytoskeleton and transmitted to the membrane by a multi-protein coat. However, the actual forces exerted by the endocytic machinery remain unknown. In this seminar, I will present a new easy-to-use strategy to measure forces in vivo that my lab recently developed. By applying this strategy to the Hip1R yeast homologue End4p, an endocytic protein central to force transmission, I will demonstrate that forces are collected and redistributed within the endocytic coat, and are between 8 and 20 pN per End4p molecule. I will also discuss how these forces are in the same range as what theory predicts, and discuss the molecular mechanisms that can be used to produce forces that large.
Associate Professor of Molecular Biophysics and Biochemistry, and of Cell Biology , International Chair LabEx Cell(n)Scale
Biologie cellulaire et Cancer (UMR144)