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PhosphoSitePlus® Resource

  • Additional protein information
  • Analytical tools


Product Includes Quantity (with Count) Solution Color
Kinase Buffer (10X) 9802 1 x 15 ml
ATP (10 mM) 9804 1 x 1 ml

Product Description

The kit provides a means of performing kinase activity assays with recombinant human IKKepsilon kinase. It includes active IKKepsilon kinase (supplied as a GST fusion protein), a biotinylated peptide substrate and a phospho-serine/threonine antibody for detection of the phosphorylated form of the substrate peptide.

Molecular Formula:

Peptide substrate, Biotin-PAK1 (Ser144)/PAK2 (Ser141) peptide: 1,775 Daltons. GST-IKKe Kinase: 110 kDa.

Peptide Core Sequence:


The NF-κB/Rel transcription factors are present in the cytosol in an inactive state, complexed with the inhibitory IκB proteins (1-3). Most agents that activate NF-κB do so through a common pathway based on phosphorylation-induced, proteasome-mediated degradation of IκB (3-7). The key regulatory step in this pathway involves activation of a high molecular weight IκB kinase (IKK) complex whose catalysis is generally carried out by three tightly associated IKK subunits. IKKα and IKKβ serve as the catalytic subunits of the kinase and IKKγ serves as the regulatory subunit (8,9). Activation of IKK depends upon phosphorylation at Ser177 and Ser181 in the activation loop of IKKβ (Ser176 and Ser180 in IKKα), which causes conformational changes, resulting in kinase activation (10-13).

Recently, two homologs of IKKalpha and IKKbeta have been described, called IKKepsilon (also known as IKK-i) and TBK-1 (also known as T2K or NAK), and activation of either of these kinases results in NFkappaB activation. The kinase domain of IKKepsilon is located in its amino-terminus, which shares 30% sequence homology with both IKKalpha and IKKbeta. IKKepsilon is expressed predominantly in immune cells, and may play a special role in the immune response (14-18).

1.  Baeuerle, P.A. and Baltimore, D. (1988) Science 242, 540-6.

2.  Beg, A.A. and Baldwin, A.S. (1993) Genes Dev 7, 2064-70.

3.  Finco, T.S. et al. (1994) Proc Natl Acad Sci USA 91, 11884-8.

4.  Brown, K. et al. (1995) Science 267, 1485-8.

5.  Brockman, J.A. et al. (1995) Mol Cell Biol 15, 2809-18.

6.  Traenckner, E.B. et al. (1995) EMBO J 14, 2876-83.

7.  Chen, Z.J. et al. (1996) Cell 84, 853-62.

8.  Zandi, E. et al. (1997) Cell 91, 243-52.

9.  Karin, M. (1999) Oncogene 18, 6867-74.

10.  DiDonato, J.A. et al. (1997) Nature 388, 548-54.

11.  Mercurio, F. et al. (1997) Science 278, 860-6.

12.  Johnson, L.N. et al. (1996) Cell 85, 149-58.

13.  Delhase, M. et al. (1999) Science 284, 309-13.

14.  Tojima, Y. et al. (2000) Nature 404, 778-82.

15.  Bonnard, M. et al. (2000) EMBO J 19, 4976-85.

16.  Shimada, T. et al. (1999) Int Immunol 11, 1357-62.

17.  Peters, R.T. et al. (2000) Mol Cell 5, 513-22.

18.  Peters, R.T. and Maniatis, T. (2001) Biochim Biophys Acta 1471, M57-62.

Data Sheets & Documentation

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
DELFIA is a registered trademark of PerkinElmer, Inc.

HTScan® IKKε Kinase Assay Kit