Cytokeratin 8 (KRT8) Antibody – Mouse Monoclonal

This gene is a member of the type II keratin family clustered on the long arm of chromosome 12. Type I and type II keratins heteropolymerize to form intermediate-sized filaments in the cytoplasm of epithelial cells. The product of this gene typically dimerizes with keratin 18 to form an intermediate filament in simple single-layered epithelial cells. This protein plays a role in maintaining cellular structural integrity and also functions in signal transduction and cellular differentiation. Mutations in this gene cause cryptogenic cirrhosis. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jan 2012]

Function: Together with KRT19, helps to link the contractile apparatus to dystrophin at the costameres of striated muscle. Ref.20

Subunit structure: Heterotetramer of two type I and two type II keratins. KRT8 associates with KRT18. Associates with KRT20. Interacts with HCV core protein and PNN. When associated with KRT19, interacts with DMD. Interacts with TCHP. Interacts with APEX1. Ref.15 Ref.16 Ref.19 Ref.20 Ref.21 Ref.23 Ref.27

Subcellular location: Cytoplasm. Nucleus › nucleoplasm

By similarity. Nucleus matrix

By similarity Ref.15 Ref.27.

Tissue specificity: Observed in muscle fibers accumulating in the costameres of myoplasm at the sarcolemma membrane in structures that contain dystrophin and spectrin. Expressed in gingival mucosa and hard palate of the oral cavity. Ref.15 Ref.20

Post-translational modification: Phosphorylation on serine residues is enhanced during EGF stimulation and mitosis. Ser-74 phosphorylation plays an important role in keratin filament reorganization.O-glycosylated. O-GlcNAcylation at multiple sites increases solubility, and decreases stability by inducing proteasomal degradation. Ref.13 Ref.30 Ref.35O-glycosylated (O-GlcNAcylated), in a cell cycle-dependent manner. Ref.13 Ref.30 Ref.35

Involvement in disease: Cirrhosis (CIRRH) [MIM:215600]: A liver disease characterized by severe panlobular liver-cell swelling with Mallory body formation, prominent pericellular fibrosis, and marked deposits of copper. Clinical features include abdomen swelling, jaundice and pulmonary hypertension.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.36

Miscellaneous: There are two types of cytoskeletal and microfibrillar keratin: I (acidic; 40-55 kDa) and II (neutral to basic; 56-70 kDa).

Sequence similarities: Belongs to the intermediate filament family.