Molecular identity of the mechanotransduction machinery in inner ear hair cells and mechanotransduction-linked hearing loss

Hearing is among the most sensitive sensory modalities in vertebrates, and its dysfunction can lead to hearing loss. Auditory perception within the inner ear relies on mechanosensitive hair cells and a sophisticated network of molecules that comprise the machinery responsible for mechanotransduction. The mechanosensory hair cells exhibit distinct structural features that enable them to transform sound vibrations into electrical signals, which are then relayed to the spiral ganglion neurons (SGNs) that are connecting between the cochlear hair cells and the cochlear nuclei with high accuracy and fidelity. Despite over 40 years of research, the precise molecular composition and assembly of the mechanotransduction channel complex within cochlear hair cells remains elusive. This review presents recent findings that provide new perspectives on the molecular components and assembly of the mechanotransduction apparatus in cochlear hair cells, as well as genetic mutations related to mechanotransduction dysfunction and hearing loss.