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MABT844

Sigma-Aldrich

Anti-Cytokeratin 8/18 Antibody, clone L2A1

clone L2A1, from mouse

Synonym(s):

Cytokeratin-8/18, Keratin type II cytoskeletal 8/Keratin type I cytoskeletal 18, Keratin-8/Keratin-18, K8/K18)

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About This Item

UNSPSC Code:
12352203
eCl@ss:
32160702
NACRES:
NA.43

biological source

mouse

antibody form

purified antibody

antibody product type

primary antibodies

clone

L2A1, monoclonal

species reactivity

human

packaging

antibody small pack of 25 μg

technique(s)

immunocytochemistry: suitable
immunoprecipitation (IP): suitable

isotype

IgGκ

UniProt accession no.

target post-translational modification

unmodified

Gene Information

human ... KRT18(3875)

General description

Cytokeratin-8/18 (UniProt: P05787/P05783; also known as Keratin, type II cytoskeletal 8/ Keratin, type I cytoskeletal 18, Keratin-8/Keratin-18, K8/K18) is encoded by the KRT8/KRT18 (also known as CYK8/CYK18) gene (Gene ID: 3856/3875) in human. Cytokeratins 8 and 18 (K8/18) are simple epithelial cell-specific intermediate filament proteins. Cytokeratin-8 is a type II, neutral to basic, protein of the intermediate filament family that together with Cytokeratin-19 (KRT19) helps to link the contractile apparatus to dystrophin at the costameres of striated muscle. Cytokeratin-8 can undergo phosphorylation on three major serine residues: Serine 23, 431, and 73. Serine 23 is shown to be highly conserved in all type II keratins. Phosphorylation at Serine 73 is reported to increase during cellular stress, including hear and drug exposure. However, under normal conditions serine 73 remains largely dephosphorylated. Cytokeratin-8 can also undergo O-glycosylation in a cell cycle-dependent manner and glycosylation increases its solubility and reduces stability by inducing proteasomal degradation. 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 KRT8 and KRT18 genes have been been linked to liver cirrhosis that is characterized by severe panlobular liver-cell swelling with Mallory body formation, prominent pericellular fibrosis, and marked deposits of copper.

Specificity

Clone L2A1 is a mouse monoclonal antibody that detects human cytokeratin 8/18.

Immunogen

KLH-conjugated Linear Peptide corresponding to a sequence from Human Cytokeratin 8/18.

Application

Anti-Cytokeratin 8/18, clone L2A1, Cat. No. MABT844, is a mouse monoclonal antibody that detects cytokeratin 8/18 and has been tested for use in Immunocytochemistry and Immunoprecipitation.
Immunoprecipitation Analysis: A representative lot detected Cytokeratin 8/18 in Immunoprecipitation applications (Haltiwanger, R.S., et. al. (1997). J Biol Chem. 272(13):8752-8; Chou, C.F., et. al. (1994). Biochem J. 298 ( Pt 2):457-63; Chou, C.F., et. al. (1993). Biochem J. 268(6):4465-72; Ku, N.O., et. al. (2000). J Cell Biol. 149(3):547-52; Lahdeniemi, I.A.K., et. al. (2017). Cell Death Differ. 24(6):984-996).

Immunocytochemistry Analysis: A representative lot detected Cytokeratin 8/18 in Immunocytochemistry applications (Chou, C.F., et. al. (1993). Biochem J. 268(6):4465-72).
Research Category
Cell Structure

Quality

Evaluated by Immunocytochemistry in HT-29 cells.

Immunocytochemistry Analysis: A 1:500 dilution of this antibody detected Cytokeratin 8/18 in HT-29 cells.

Target description

~53.70 kDa and 48.06 kDa, respectively for cytokeratin 8 and 18 calculated. Uncharacterized bands may be observed in some lysate(s).

Physical form

Format: Purified
Protein G purified
Purified mouse monoclonal antibody IgG in buffer containing 0.1 M Tris-Glycine (pH 7.4), 150 mM NaCl with 0.05% sodium azide.

Storage and Stability

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

Other Notes

Concentration: Please refer to lot specific datasheet.

Disclaimer

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.

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C F Chou et al.
The Biochemical journal, 298 ( Pt 2), 457-463 (1994-03-01)
We describe the characterization of an acidic glycoprotein (molecular mass approximately 85 kDa) that associates with keratin intermediate filaments of 'simple'-type epithelia. Using a number of anti-keratin monoclonal antibodies, the 85 kDa glycoprotein was identified by co-immunoprecipitation with keratin polypeptides
N O Ku et al.
The Journal of cell biology, 149(3), 547-552 (2000-05-03)
Keratin polypeptides 8 and 18 (K8/18) are intermediate filament (IF) proteins that are expressed in glandular epithelia. Although the mechanism of keratin turnover is poorly understood, caspase-mediated degradation of type I keratins occurs during apoptosis and the proteasome pathway has
C F Chou et al.
The Journal of biological chemistry, 268(6), 4465-4472 (1993-02-25)
Arrest of the human colonic cell line HT29 at the G2/M phase of the cell cycle resulted in changes in keratin assembly that were coupled with a significant increase in the O-linked glycosylation and serine phosphorylation of keratin polypeptides 8
R S Haltiwanger et al.
The Journal of biological chemistry, 272(13), 8752-8758 (1997-03-28)
O-Linked N-acetylglucosamine (O-GlcNAc) is a ubiquitous and abundant protein modification found on nuclear and cytoplasmic proteins. Several lines of evidence suggest that it is a highly dynamic modification and that the levels of this sugar on proteins may be regulated.
Iris A K Lähdeniemi et al.
Cell death and differentiation, 24(6), 984-996 (2017-05-06)
Keratins (K) are intermediate filament proteins important in stress protection and mechanical support of epithelial tissues. K8, K18 and K19 are the main colonic keratins, and K8-knockout (K8-/-) mice display a keratin dose-dependent hyperproliferation of colonic crypts and a colitis-phenotype.

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