The vertebrate inner ear is in charge of transforming mechanical stimuli from sound and head movement into electrical signals that are sent to the brain.   This so-called "mechanotransduction process" requires exquisite precision and sensitivity, as well as robustness to withstand strong mechanical stimuli. At the core of inner-ear mechanotransduction are hair cells and hair-cell tip links, the fine protein filaments that pull open mechanosensitive ion channels, thereby depolarizing hair cells and initiating perception. In a paper just published in Nature, a team from Rachelle Gaudet’s lab in MCB and David P. Corey’s lab (HHMI/Harvard Medical School) has determined new crystal structures of key components of the hair-cell tip link. The structures, along with complementary biochemical experiments and molecular dynamics simulations, sheds light on the molecular mechanics of hair-cell transduction and new interaction mechanisms for cadherins, a large protein family implicated in tissue and organ morphogenesis, as well as neuronal connectivity.