KRT31

Keratin 31 (KRT31), also known as cytokeratin 31 (CK31), is a type I intermediate filament protein. It is predominantly expressed in the cuticle layer of hair follicles, where it heterodimerizes with type II keratins to form a robust cytoskeletal network. This structure is critical for maintaining the mechanical strength and integrity of hair shafts, supporting normal hair growth and texture.
Mutations in KRT31 are linked to autosomal dominant woolly hair syndrome, causing tightly curled, fine hair from birth. It interacts with the Wnt/β-catenin pathway, which regulates hair follicle development. Current research explores small molecules targeting keratin filament stability or Wnt signaling to address KRT31-related hair disorders, though specific therapeutic agents remain in preclinical stages.