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PhosphoSitePlus® Resource

  • Additional protein information
  • Analytical tools


Product Description

The Phospho-(Ser) Kinase Substrate Antibody Sampler Kit provides a fast and economical means of evaluating several phospho-Ser kinase substrates. The kit contains enough primary and secondary antibody to perform two Western blot experiments.

Specificity / Sensitivity

Each antibody detects endogenous levels of phospho-(Ser) proteins of specific kinase substrate groups. For more detailed information please see datasheet for this product.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with phosphopeptides containing the kinase substrate motif and purified by protein A and peptide affinity chromatography.

Monoclonal antibody is produced by immunizing animals with synthetic phospho-MAPK/CDK substrate and phospho-CDKs substrate peptides.

Mouse monoclonal antibody is produced by immunizing animals with phospho-(Ser) 14-3-3 binding motif peptides .

Phospho-(Ser) kinases and phosphatases play critical roles in a wide range of biological processes. Each phospho-(Ser) kinase phosphorylates serine within a specific motif. The MAPK and CDK families of serine protein kinases phosphorylate serine followed by proline residue (1-3). The consensus amino acid sequence for CDK substrate is (K/R)(S*)PX(K/R), where X denotes any one of the 20 amino acids and S* is the phosphorylation site (4-6). MAPK phosphorylates substrates with the concensus sequence PX(S*)P. The 14-3-3 proteins are a highly conserved family of proteins involved in the regulation of cell survival, apoptosis, proliferation and checkpoint control (7-11). Binding of 14-3-3 is mediated through phospho-serine-containing proteins (12). Two different phospho-serine containing motifs are found using a degenerate phospho-serine-oriented peptide library technique, RSXS*XP and RXY/FXS*XP (12). Motif 1 (Arg/Lys and Ser at positions -3 and -2, phospho-Ser at position 0, and Pro at position +2) is found in critical regulatory proteins including Bad, cdc25C, FoxO3A, PKC and c-Raf (11, 13). Motif 2 (RXY/FXS*XP) is found in critical regulatory proteins including cdc25A, cdc25B, PKCγ, IRS-1 and BCR (12). Although Phospho-(Ser) Arg-X-Tyr/Phe-X-pSer Motif Antibody binds 14-3-3 binding motif 2 with no requirement for proline in the +2 position, it provides a powerful tool for the discovery and characterization of potential 14-3-3 binding motif 2-containing proteins or other proteins with the RXY/FXS* motif. Antibodies specific to particular kinase substrates are invaluable reagents in determining kinase activity and identifying potential new kinase substrates. CST has developed antibodies that recognize phosphorylated serine within the context of a protein motif that is phosphorylated by MAPK/CDK, CDKs or 14-3-3. As shown by DELFIA or ELISA, each phospho-(Ser) kinase substrate antibody in this sampler kit is specific to its kinase substrate motif.

1.  Pearson, R.B. and Kemp, B.E. (1991) Methods Enzymol 200, 62-81.

2.  Karin, M. (1994) Curr Opin Cell Biol 6, 415-24.

3.  Lewis, T.S. et al. (1998) Adv Cancer Res 74, 49-139.

4.  Songyang, Z. et al. (1996) Mol Cell Biol 16, 6486-93.

5.  Songyang, Z. (1999) Prog Biophys Mol Biol 71, 359-72.

6.  Holmes, J.K. and Solomon, M.J. (1996) J Biol Chem 271, 25240-6.

7.  Aitken, A. (1995) Trends Biochem Sci 20, 95-7.

8.  Zha, J. et al. (1996) Cell 87, 619-628.

9.  Piwnica-Worms, H. (1999) Nature 401, 535, 537.

10.  Tzivion, G. et al. (1998) Nature 394, 88-92.

11.  Xing, H. et al. (2000) . EMBO J. 19, 349-358.

12.  Muslin, A.J. et al. (1996) Cell 84, 889-97.

13.  Yaffe, M.B. et al. (1997) Cell 91, 961-71.

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
U.S. Patent No. 7,429,487, foreign equivalents, and child patents deriving therefrom.
Use of Cell Signaling Technology (CST) Motif Antibodies within certain methods (e.g., U.S. Patents No. 7,198,896 and 7,300,753) may require a license from CST. For information regarding academic licensing terms please have your technology transfer office contact CST Legal Department at For information regarding commercial licensing terms please contact CST Pharma Services Department at

Phospho-(Ser) Kinase Substrate Antibody Sampler Kit