Applications Key: W=Western Blotting Reactivity Key: H=Human M=Mouse R=Rat B=Bovine Dg=Dog Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.
Phospho-IκBε (Ser18/22) Antibody detects endogenous levels of IκBε only when phosphorylated at serines 18 and 22. No cross-reactivity was detected with other family members at physiological conditions.
Source / Purification
Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding serine 18/22 of human IκBε. Antibodies are purified by protein A and peptide affinity chromatography.
Western Blotting
Western blot analysis of extracts from 293 cells treated with TNF-α (20 ng/ml) for the indicated times, using Phospho-IκBε (Ser18/22) Antibody.
Background
The NF-κB/Rel transcription factors are present in the cytosol in an inactive state complexed with the inhibitory IκB proteins (1-3). Activation occurs via phosphorylation of IκBα at Ser32 and Ser36 followed by proteasome-mediated degradation that results in the release and nuclear translocation of active NF-κB (3-7). IκBα phosphorylation and resulting Rel-dependent transcription are activated by a highly diverse group of extracellular signals including inflammatory cytokines, growth factors, and chemokines. Kinases that phosphorylate IκB at these activating sites have been identified (8).
The regulation of IκBβ and IκBε is similar to that of IκBα. However, the phosphorylation and ubiquitin-mediated degradation of these proteins occurs with much slower kinetics (9). IKK phosphorylation of IκBβ occurs at Ser19 and Ser23, while IκBε can be phosphorylated at Ser18 and Ser22 (10).