Keratin 4

Keratin 4 (KRT4) is a type of keratin protein that is primarily found in the non-cornified squamous epithelium, which includes the oral mucosa, esophagus, and cornea. It is one of the many keratins that contribute to the structural integrity of epithelial cells.

Structure

Keratin 4 is a type II keratin, which means it is acidic and must pair with a type I keratin to form a functional keratin intermediate filament. It is typically paired with Keratin 13 (KRT13), a type I keratin, in the non-cornified squamous epithelium.

Function

The primary function of Keratin 4 is to provide structural support to the cells in which it is expressed. It helps to maintain the shape and integrity of the cell, and protects it from mechanical stress. In addition, Keratin 4 also plays a role in the regulation of cell growth and differentiation.

Clinical significance

Mutations in the KRT4 gene, which encodes Keratin 4, can lead to a variety of skin disorders. These include White Sponge Nevus (WSN), a rare autosomal dominant disorder characterized by white, spongy plaques in the oral mucosa, and Hereditary Mucoepithelial Dysplasia (HMD), a rare autosomal dominant disorder characterized by chronic inflammation and infection of the mucous membranes.

See also

• Keratin
• Keratin 13
• White Sponge Nevus
• Hereditary Mucoepithelial Dysplasia