Cell Signaling Technology

Product Pathways - NF-kB Signaling

Phospho-IKKε (Ser172) (D1B7) Rabbit mAb #8766

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP H (M) (R) (Mk) (Dg) Endogenous 80 Rabbit IgG

Applications Key:  W=Western Blotting  IP=Immunoprecipitation
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey  Dg=Dog
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-IKKε (Ser172) (D1B7) Rabbit mAb recognizes endogenous levels of IKKε protein only when phosphorylated at Ser172.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser172 of human IKKε protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from THP-1 cells, differentiated with TPA #4174 (80 nM, overnight) followed by treatment with LPS (1 μg/ml, indicated times), using Phospho-IKKε (Ser172) (D1B7) Rabbit mAb (upper) or IKKε (D20G4) Rabbit mAb #2905 (lower).

Background

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 IKKα and IKKβ have been described, called IKKε (also known as IKK-i) and TBK1 (also known as T2K or NAK), and activation of either of these kinases results in NF-κB activation. IKKε contains the kinase domain in its amino terminus, which shares 30% identity to that of IKKα or IKKβ. IKKε is expressed mainly in immune cells, and may play a special role in the immune response (14-18). IKKε and TBK1 kinase capabilities are activated by phosphorylation at Ser172 within their activation loops (19). IRF-3, a substrate for IKKε and TBK1, plays a critical role in innate immune responses (20).

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  18. Peters, R.T. and Maniatis, T. (2001) Biochim Biophys Acta 1471, M57-62.
  19. Kishore, N. et al. (2002) J Biol Chem 277, 13840-7.
  20. Fitzgerald, K.A. et al. (2003) Nat Immunol 4, 491-6.

Application References

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For Research Use Only. Not For Use In Diagnostic Procedures.

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