Beta-tectorin is a 329 amino acid secreted protein that contains one zona pellucida (ZP) domain. While it may form homomeric filaments after self-association, Beta-tectorin may also form heteromeric filaments when it associates with ?tectorin. The presence of a hydrophobic C-terminus preceded by a potential cleavage site strongly suggests that tectorins are synthesized as glycosylphosphatidylinositol-linked, membrane-bound precursors. Tectorins are targeted to the apical surface of the inner ear epithelia and proteolytically released into the extracellular compartment. Beta-tectorin is one of the major non-collagenous components of the tectorial membrane. The tectorial membrane is an extracellular matrix of the inner ear that covers the neuroepithelium of the cochlea and contacts the stereocilia bundles of specialized sensory hair cells. Sound induces movement of these hair cells relative to the tectorial membrane, deflects the stereocilia and leads to fluctuations in hair-cell membrane potential, transducing sound into electrical signals.