Cytokeratin 12 (CK12)

Keratin 12 is a keratin found expressed in corneal epithelia. Mutations in the gene encoding this protein lead to Meesmann corneal dystrophy. To elucidate the function of keratin 12, Kao et al. (1996) created knockout mice lacking the Krt1.12 gene by gene targeting techniques. The heterozygous mice appeared normal. Homozygous mice developed normally and suffered mild corneal epithelial erosion. The corneal epithelia were fragile and could be removed by gentle rubbing of the eyes or brushing. The corneal epithelium of the homozygotes did not express keratin 12 as judged by immunohistochemistry, Western immunoblot analysis with epitope-specific anti-keratin 12 antibodies, Northern hybridization, and in situ hybridization with an antisense keratin 12 riboprobe.