stereocilin

Stereocilin is a protein encoded by the STRC gene in humans. It is a component of the hair bundle of cochlear and vestibular hair cells, localized to the apical surface of stereocilia where it participates in the formation of extracellular linkages that help maintain bundle architecture.

In the sensory hair bundle, stereocilin is associated with the connections between adjacent stereocilia, including lateral and upper-link structures that stabilize the bundle as it deflects in response to sound or head movement. Through its role in maintaining these connections, stereocilin supports the proper function of mechanotransduction, the process by which mechanical stimuli are converted into electrical signals in hair cells.

Genetic and clinical notes indicate that pathogenic variants or deletions of STRC can cause autosomal recessive non-syndromic hearing loss (DFNB16). Affected individuals typically present with congenital or early-onset sensorineural hearing loss, often mild to moderate in severity, without additional syndromic features. Carriers are usually asymptomatic. The STRC gene is located on chromosome 15 and has been identified as a relatively common cause of recessive deafness in various populations.

Research in animal models, including stereocilin knockout studies, shows disrupted hair bundle morphology and impaired mechanotransduction, underscoring stereocilin’s role in hair bundle integrity. Ongoing studies seek to clarify the precise molecular interactions of stereocilin within the tip-link and lateral-link networks and to understand its broader implications for cochlear resilience to aging and environmental stress.