The mechanics of membrane proteins is a signature of biological function

International audienceBeyond structure, the mechanics of plasma membrane components is of key importance to biological function. Nanoscale mechanics is however poorly described due to the lack of suitable experimental tools. Here, we combined atomic force microscopy and nanomechanical mapping to analyze the structure and mechanical properties of native eye lens cell membranes. Lens membranes mainly comprise two proteins; aquaporin 0 and connexin, forming respectively thin and gap intercellular junctions that sustain mechanical stress during accommodation. Our results reveal the mechanical heterogeneity of the plasma membrane, allowing examination of the mechanical nanoenvironment of individual proteins and the flexibility of supramolecular assemblies. The remarkable rigidity of gap junctions suggests their role as stable intercellular adhesion complexes ensuring maintenance of thin junctions, which form more flexible supramolecular complexes capable of sustaining pressure differences between cells. Our work proposes the mechanical properties of individual proteins and protein domains directly related to biological function as a novel molecular signature