Cochlin (COCH)

Cochlin is a highly conserved extracellular matrix protein encoded by the COCH gene, predominantly expressed in the cochlea and vestibule of the inner ear, where it is the most abundant non-collagenous protein[1][2][3][5]. Its structure comprises an N-terminal LCCL domain and two von Willebrand factor A (VWFA) domains[1][2][5]. Cochlin is critical for maintaining structural integrity and biophysical properties of the inner ear sensory matrix by binding to collagen and other ECM components[3][5]. Pathogenic mutations in the COCH gene disrupt normal processing and secretion of cochlin, leading to DFNA9—a progressive, adult-onset, autosomal dominant sensorineural hearing loss and vestibular disorder—through abnormal protein aggregation and cytotoxicity[1][2][3][5]. In immune tissues (spleen, lymph nodes), a cleaved form of cochlin enhances innate immune responses, while in the eye, its abnormal presence in the trabecular meshwork contributes to glaucoma by disrupting ECM homeostasis and modulating mechanosensation[1][3]. Cochlin’s multifunctional roles extend to possible contributions in autoimmune inner ear disease, with evidence of antibody and T cell responses against the protein in some patients[3]. Currently, cochlin is not a therapeutic drug target, and there are no known drugs directly targeting this protein.

Other names

COCHCOCH-5B2COCH5B2UNQ257/PRO294DFNA9DFNB110D12H14S564EAW122937coagulation factor C homolog