Keratin 12

Keratin 12 (KRT12) is a type of keratin protein that is specifically expressed in the corneal epithelium, the outermost layer of the eye. It is encoded by the KRT12 gene in humans. Mutations in this gene are associated with Meesmann Corneal Dystrophy (MCD), a rare genetic disorder that affects the cornea.

Structure

Keratin 12 is a type of intermediate filament protein. Like all keratins, it is characterized by a central alpha-helical rod domain that is flanked by non-helical head (N-terminal) and tail (C-terminal) domains. The rod domain is responsible for the formation of coiled-coil dimers, the basic building blocks of the keratin filament network.

Function

Keratin 12, together with its binding partner Keratin 3, forms the intermediate filament network in the corneal epithelial cells. This network provides mechanical strength and resilience to the cornea, protecting it from physical and environmental stress. It also plays a role in maintaining the barrier function of the cornea, preventing the entry of foreign substances into the eye.

Clinical significance

Mutations in the KRT12 gene can lead to the development of Meesmann Corneal Dystrophy. This condition is characterized by the formation of small, clear, bubble-like cysts in the corneal epithelium, which can cause blurred vision, light sensitivity, and occasional pain. Currently, there is no cure for MCD, but treatments are available to manage the symptoms.

See also

• Keratin
• Meesmann Corneal Dystrophy
• Corneal epithelium