Keratin 5

Keratin 5 is a type of keratin protein that is primarily found in the basal layer of the epidermis, the outermost layer of the skin. It is encoded by the KRT5 gene in humans. Keratin 5, along with keratin 14, forms the cytoskeleton of epithelial cells, providing structural integrity and playing a crucial role in cell proliferation and differentiation.

Structure

Keratin 5 is a type II keratin, one of the two types of keratins found in vertebrates. It is a fibrous protein that forms intermediate filaments, which are key components of the cytoskeleton. The structure of keratin 5 is characterized by a central alpha-helical rod domain, flanked by non-helical head and tail domains. The rod domain is involved in the formation of coiled-coil dimers with type I keratins, such as keratin 14.

Function

Keratin 5 plays a critical role in maintaining the structural integrity of the skin and other epithelial tissues. It forms a network of intermediate filaments with keratin 14, which provides mechanical resilience to the cells, protecting them from physical stress. In addition to its structural role, keratin 5 is also involved in several cellular processes, including cell proliferation, differentiation, and migration.

Clinical significance

Mutations in the KRT5 gene can lead to a rare genetic skin disorder known as epidermolysis bullosa simplex (EBS). EBS is characterized by the formation of blisters and erosions on the skin in response to minor mechanical trauma. Most mutations in KRT5 that cause EBS are missense mutations, which result in a single amino acid change in the keratin 5 protein. This disrupts the formation of the intermediate filament network, weakening the mechanical strength of the skin.

See also

• Keratin
• Keratin 14
• Epidermolysis bullosa simplex
• Cytoskeleton
• Epidermis