SÉMINAIRE CONJOINT DEPARTEMENTS DE PHYSIQUE, MECANIQUE ET DE BIOLOGIE 

Dr. Martin LENZ
CNRS - Université Paris-Sud

Jeudi 21 Janvier 2016 à 11h00                                                                                                  

Ecole Polytechnique, Amphithéâtre Becquerel

Le séminaire sera donné en anglais.

Dissecting active cellular processes

Biological motion and forces originate from mechanically active proteins. These nanometric machines interact and collectively form micron-sized structures perfectly tuned to their fundamentally out-of-equilibrium functions. While both individual proteins and the resulting large-scale cellular behaviors are well characterized, understanding the relationship between these two scales remains a major challenge in both physics and cell biology.

We bridge this gap through multiscale statistical mechanics models of émergent nonequilibrium material properties in two classes of biological systems. Working on membrane-protein interactions, we theoretically infer nanometer-scale information from our close collaborators’well-controlled, large-scale in vitro experiments. Considering the
actomyosin cytoskeleton, we introduce and validate a new paradigm for the emergence of active contractile stresses from microscopic motors that do not have any intrinsic preference for contraction. This work has the potential to redefine a cornerstone of our understanding of cellular motion, and opens the way for the development of rigorous, generic theoretical frameworks to bridge the gap between the microscopic and the macroscopic in living active matter.