Anti-phospho-cytokeratin-18 (K18) (Ser33) Antibody, clone IB4

Keratin, type I cytoskeletal 18 (UniProt: P05783; also known as Cell proliferation-inducing gene 46 protein, Cytokeratin-18, CK-18, Keratin-18, K18) is encoded by the KRT18 (also known as CYK18, PIG46) gene (Gene ID: 3875) in human. Cytokeratin-18 is a type I, acidic, protein that is expressed in colon, placenta, and liver. Higher expression levels have been reported in lymph nodes of breast carcinoma. Cytokeratin-18 is involved in the uptake of thrombin-antithrombin complexes by hepatic cells. Upon phosphorylation, it plays a role in filament reorganization. It is proteolytically cleaved by caspases during epithelial cell apoptosis and this cleavage is shown to occur at Asp-238. Phosphorylation of cytokeratin-18 at serine 33 is shown to increase during mitosis in cultured cells and in regenerating liver. Serine 33 phosphorylation is considered to be essential for its association with 14-3-3 proteins and has a role in keratin organization and distribution. Cytokeratin-18 can undergo O-glycosylation, which results in its increased solubility and reduction in its stability. Mutations in KRT18 gene are known to cause liver cirrhosis characterized by severe panlobular liver-cell swelling with Mallory body formation, prominent pericellular fibrosis, and marked deposits of copper.

Clone IB4 specifically detects human cytokeratin-18 phosphorylated on serine 33.

KLH-conjugated linear peptide corresponding to 13 amino acids surrounding phosphorylated serine 33 (initiator methionine removed) from the N-terminal region of human cytokeratin-18.

Anti-phospho-cytokeratin-18 (K18) (Ser33), clone IB4, Cat. No. MABT875, is a mouse monoclonal antibody that detects type I cytoskeletal-18 and has been tested for use in Immunocytochemistry, Immunofluorescence, Immunoprecipitation, and Western Blotting.

Immunocytochemistry Analysis: A representative lot detected phospho-cytokeratin-18 (K18) (Ser33) in immunocytochemistry applications (Ku, N.O., et. al. (1998). EMBO J. 17(7):1892-906).

Immunoprecipitation Analysis: A representative lot immunoprecipitated phospho-cytokeratin-18 (K18) (Ser33) in immunoprecipitation applications (Ku, N.O., et. al. (1998). EMBO J. 17(7):1892-906).

Immunofluorescence Analysis: A representative lot detected phospho-cytokeratin-18 (K18) (Ser33) in Immunofluorescence applications (Ku, N.O., et. al. (1998). EMBO J. 17(7):1892-906).

Western Blotting Analysis: A representative lot detected phospho-cytokeratin-18 (K18) (Ser33) in Western Blotting applications (Yoon, K.H., et. al. (2001). J Cell Biol. 153(3):503-16).

Research Category
Cell Structure

Evaluated by Western Blotting in lysates from HeLa cells treated with Calyculin A/Okadaic Acid.

Western Blotting Analysis: 2 µg/mL of this antibody detected phospho-cytokeratin-18 (K18) (Ser33) in lysate from HeLa cells treated with Calyculin A/Okadaic Acid.

~48 kDa observed; 48.06 kDa calculated. Uncharacterized bands may be observed in some lysate(s).

Protein G purified

Format: Purified

Purified mouse monoclonal antibody IgG1 in buffer containing 0.1 M Tris-Glycine (pH 7.4), 150 mM NaCl with 0.05% sodium azide.

Stable for 1 year at 2-8°C from date of receipt.

Concentration: Please refer to lot specific datasheet.

Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.