Our skin and mucous membranes are protected by epithelial cells. This ‘barrier’ tissue performs its function thanks to specialized structures called ‘junctions’. They ensure cell cohesion and regulate exchanges across the space between cells. Researchers have studied the role of a specific protein, gamma-actin, in the organization and mechanics of epithelial cells and their junctions. Their work reveals a mechanism of interdependence of different forms of the cytoskeletal proteins actin and myosin, and their functions. The team also demonstrates the key role of gamma-actin in the rigidity of cell membranes and the dynamics of junctional proteins, which may provide a mechanism of hearing loss.