Myosin-IIIa

Myosin-IIIa is a protein that in humans is encoded by the MYO3A gene. It is a member of the myosin superfamily, which are actin-dependent motor proteins with diverse functions including regulation of cytokinesis, vesicle transport, and cell motility.

Structure

Myosin-IIIa is a unique member of the myosin family due to its kinase domain, which is not found in other myosins. The protein has a motor domain, a neck domain with three IQ motifs, and a tail domain. The tail domain contains a PDZ domain-binding motif, which allows it to interact with other proteins.

Function

Myosin-IIIa is involved in the regulation of actin filament dynamics. It is thought to play a role in hearing by maintaining the structural integrity of inner ear hair cells. Mutations in the MYO3A gene have been associated with a form of autosomal dominant progressive hearing loss.

Clinical significance

Mutations in the MYO3A gene can cause DFNB30, a form of non-syndromic hearing loss. This condition is characterized by moderate to severe hearing impairment that begins in early childhood and worsens over time. There is currently no cure for DFNB30, but hearing aids and cochlear implants can help to improve hearing ability.

See also

• Myosin
• Non-syndromic hearing loss and deafness