prestin

Prestin is a motor protein that powers the electromotility of outer hair cells in the mammalian cochlea. It is encoded by the SLC26A5 gene and belongs to the SLC26 family of anion transporters, although prestin functions primarily as a voltage-driven motor rather than a conventional transporter.

In outer hair cells, changes in membrane potential cause prestin to change its conformation, resulting in rapid length changes of the cell. This somatic motility feeds back into the cochlear partition, amplifying basilar membrane motion and improving auditory sensitivity and frequency discrimination. The voltage-dependent charge movements associated with prestin give rise to nonlinear capacitance, a characteristic hallmark of its motor function.

Prestin is most abundantly expressed in outer hair cells, and its activity is essential for normal mammalian hearing. Mice lacking prestin exhibit an absence of electromotility, reduced cochlear amplification, and elevated auditory thresholds. Heterozygous mice show intermediate phenotypes, indicating that prestin function scales with expression level.

Prestin’s pivotal role in the cochlear amplifier was established in the late 1990s and early 2000s, and it has since remained a central focus in hearing research. While substantial progress has been made in understanding its voltage-to-force mechanism, the precise molecular details continue to be investigated, along with its regulation and potential implications for hearing loss therapies.