Anti-phospho-Keratin-8 Antibody (Ser23)

Keratin, type II cytoskeletal 8 (UniProt P05787; also known as CK-8, Cytokeratin-8, K8, Keratin-8, Type-II keratin Kb8) is encoded by the KRT8 (also known as CYK8) gene (Gene ID 3856) in human. Cytokeratin-8 (Keratin-8 or K8) belongs to a family of highly conserved epithelial-specific intermediate filament (IF) proteins that play an important role in the mechanical stability and integrity of epithelial cells and tissues. Each epithelium is characterized by its unique keratin expression pattern. Keratin 8 is a type II intermediate filament protein found in simple epithelia, where it pairs with keratin 18 (K8/KI8) and plays an important role in protecting cells from stress, injury, and apoptosis. The structure and function of K8/18 are regulated by posttranslational modifications, including glycosylation, ubiquitination, and phosphorylation. K8 has been reported to be phosphorylated on Ser8, Ser23, Ser73, and Ser431 by various protein kinases. PKCepsilon is reported to mediate K8 phosphorylation on Ser8 and Ser23, p38 and PKCdelta are responsible for K8 Ser73 phosphorylation, while ERK and JNK are involved in K8 Ser431 phosphorylation.

This rabbit polyclonal antibody detected the target phospho band only in lysates from phosphatase inhibitors-treated, but not untreated HeLa cells. Antibody blocking by the immunogen peptide, but not the corresponding nonphosphorylated peptide prior to immunoblotting abolished target band detection. The Ser23 designation is based on human keratin-8 sequence with initiator Met1 removed. The phosphorylation site sequence in mouse/rat (-SSR(pS)YT-) differs from that of human (-SSR(pS)FT-) by a single Phe24-to-Tyr24 switch (F24Y). Cross-reactivity of this polyclonal antibody toward murine and rat species is likely, but has not been confirmed.

KLH-conjugated linear peptide corresponding to the phosphorylation site sequence containing the phosphorylated target serine.

Peptide Inhibition Assay: Preincubation of a representative lot with the immunogen phosphopeptide, but not the corresponding nonphosphopeptide, abolished target band detection by Western blotting analysis of 10 µg lysate from phosphatase inhibitors-treated HeLa cells.

Research Category
Cell Structure

This rabbit polyclonal Anti-phospho-Keratin-8 (Ser23), Cat. No. ABT1372 is validated for use in Peptide Inhibition Assay and Western Blotting for the detection of Keratin 8 phosphorylated at serine 23.

Evaluated by Western Blotting in HeLa cells lysate.

Western Blotting Analysis: A 1:1,000 dilutiion of this antibody detected keratin-8 Ser23 phosphorylation in 10 µg of lysate from phosphatase inhibitors-treated, but not untreated, HeLa cells.

~54 kDa observed. 53.57/56.48 kDa (isoform 1/2) calculated (Met1 removed). Uncharacterized bands may be observed in some lysate(s).

Affinity purified.

Purified rabbit polyclonal antibody 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.

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