CST, 4921S, Phospho-IkappaB beta (Thr19/Ser23) Antibody

Polyclonal Antibody for studying IkB-beta (Thr19/Ser23) phosphate. Validated for Western Blotting. Highly specific and rigorously validated in-house, Phospho-IkappaB beta (Thr19/Ser23) Antibody (CST #4921) is ready to ship. Product Usage Information Western Blotting: 1:1000 Storage Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at -20°C. Do not aliquot the antibody. Protocol Available protocols: Western Blotting Specificity / Sensitivity Phospho-IkappaB beta (Thr19/Ser23) Antibody detects endogenous levels of human IκBβ only when phosphorylated at threonine 19 and serine 23. This antibody also recognizes phosphorylation at Ser19/Ser23 also reported as the sequence for IκBβ. Species Reactivity: Human Source / Purification Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues of human IκBβ surrounding Thr19/Ser23. Antibodies are purified by protein A and affinity chromatography. 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). The human sequence of IκB-β has also been reported to contain a threonine at position 19 suggesting that phosphorylation could be Thr19/Ser23 (11). Alternate Names I-kappa-B-beta; IkappaBbeta; IkB-B; IkB-beta; IKBB; NF-kappa-B inhibitor beta; NF-kappa-BIB; NFKB inhibitor beta; NFKBIB; nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, beta; Thyroid receptor-interacting protein 9; TR-interacting protein 9; TRIP-9; TRIP9 Specification REACTIVITY: H SENSITIVITY: Endogenous MW (kDa): 48 to 50 SOURCE: Rabbit