Cell Signaling Technology

Product Pathways - Cytoskeletal Signaling

Phospho-Keratin 17 (Ser44) Antibody #3519

Applications Reactivity Sensitivity MW (kDa) Source
W F H (Mk) Endogenous 49 Rabbit

Applications Key:  W=Western Blotting  F=Flow Cytometry
Reactivity Key:  H=Human  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Phospho-Keratin 17 (Ser44) Antibody detects endogenous levels of keratin 17 only when phosphorylated on Ser44.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to amino acids surrounding Ser44 of human keratin 17. Antibodies are purified by Protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts of HeLa cells, either untreated or treated with nocodazole, using Phospho-Keratin 17 (Ser44) Antibody (upper) or Keratin 17 #3984 (lower).

Flow Cytometry

Flow Cytometry

Flow cytometric analysis of HeLa cells using Phospho-Keratin17 (Ser44) Antibody versus propidium iodide (DNA content). The boxed population indicates phospho-Keratin17 (Ser77)-positive cells.

Background

Keratins (cytokeratins) are intermediate filament proteins that are mainly expressed in epithelial cells. Keratin heterodimers composed of an acidic keratin (or type I keratin, keratins 9 to 23) and a basic keratin (or type II keratin, keratins 1 to 8) assemble to form filaments (1,2). Keratin isoforms demonstrate tissue- and differentiation-specific profiles that make them useful as biomarkers (1). Mutations in keratin genes are associated with skin disorders, liver and pancreatic diseases, and inflammatory intestinal diseases (3-6).

Keratin 17 has been shown to be involved in wound healing, a process that requires rapid remodelling of the cytoskeleton (7). Another process that requires cytoskeletal remodelling is cell growth. It has been shown that in keratin 17 null keratinocytes that signaling through the Akt/mTOR pathway fails to produce an increase in translation, cell size or growth, and that this defect is associated with abnormal localization of 14-3-3σ. Since in normal cells, 14-3-3σ associates with keratin 17, a model has been proposed whereby signaling through Akt/mTOR produces a sequestration of 14-3-3σ in the cytosol via its interaction with keratin 17, and this sequestration by keratin 17 is required for translation and cell growth. Phosphorylation of keratin 17 on Ser 44 is thought to provide a docking site for 14-3-3σ binding (8).

  1. Moll, R. et al. (1982) Cell 31, 11-24.
  2. Chang, L. and Goldman, R.D. (2004) Nat Rev Mol Cell Biol 5, 601-13.
  3. Ramaekers, F.C. and Bosman, F.T. (2004) J Pathol 204, 351-4.
  4. Lane, E.B. and McLean, W.H. (2004) J Pathol 204, 355-66.
  5. Zatloukal, K. et al. (2004) J Pathol 204, 367-76.
  6. Owens, D.W. and Lane, E.B. (2004) J Pathol 204, 377-85.
  7. Paladini, R.D. et al. (1996) J Cell Biol 132, 381-97.
  8. Kim, S. et al. (2006) Nature 441, 362-5.

Application References

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This product is intended for research purposes only. The product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

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