Cell Signaling Technology

Product Pathways - NF-kB Signaling

Phospho-IRF-3 (Ser396) (4D4G) Rabbit mAb #4947

Applications Reactivity Sensitivity MW (kDa) Isotype
W H M Endogenous 45-55 Rabbit IgG

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  M=Mouse
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-IRF-3 (Ser396) (4D4G) Rabbit mAb detects endogenous levels of IRF-3 when phosphorylated at Ser396.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser396 of human IRF-3.

Western Blotting

Western Blotting

Western blot analysis of extracts from HT29 and THP1 cells, control or plpC-transfected (1 hour), using Phospho-IRF-3 (Ser396) (4D4G) Rabbit mAb.

Background

Interferon regulatory factors (IRFs) comprise a family of transcription factors that function within the Jak/Stat pathway to regulate interferon (IFN) and IFN-inducible gene expression in response to viral infection (1). IRFs play an important role in pathogen defense, autoimmunity, lymphocyte development, cell growth, and susceptibility to transformation. The IRF family includes nine members: IRF-1, IRF-2, ISGF3γ/p48, IRF-3, IRF-4 (Pip/LSIRF/ICSAT), IRF-5, IRF-6, IRF-7, and IRF-8/ICSBP. All IRF proteins share homology in their amino-terminal DNA-binding domains. IRF family members regulate transcription through interactions with proteins that share similar DNA-binding motifs, such as IFN-stimulated response elements (ISRE), IFN consensus sequences (ICS), and IFN regulatory elements (IRF-E) (2).

IRF-3 can inhibit cell growth and plays a critical role in controlling the expression of genes in the innate immune response (1-4). In unstimulated cells, IRF-3 is present in the cytoplasm. Viral infection results in phosphorylation of IRF-3 and leads to its translocation to the nucleus where it activates promoters containing IRF-3-binding sites. Phosphorylation of IRF-3 occurs at a cluster of C-terminal serine and threonine residues (between 385 and 405) leading to its association with the p300/CBP coactivator protein that promotes DNA binding and transcriptional activity (5). During infection, IRF-3 is likely activated through a pathway that includes activation of Toll-like receptors and of a kinase complex that includes IKKε and TBK1 (6,7). IRF-3 is phosphorylated at Ser396 following viral infection, expression of viral nucleocapsid, and double stranded RNA treatment. These events likely play a role in activation of IRF-3 (8).

  1. Taniguchi, T. et al. (2001) Annu Rev Immunol 19, 623-55.
  2. Honda, K. and Taniguchi, T. (2006) Nat Rev Immunol 6, 644-58.
  3. Hiscott, J. et al. (1999) J. Interferon Cytokine Res. 19, 1-13.
  4. Kim, T.Y. et al. (2003) J. Biol. Chem. 278, 15272-15278.
  5. Yoneyama, M. et al. (2002) J. Interferon Cytokine Res. 22, 73-76.
  6. Fitzgerald, K.A. et al. (2003) Nat. Immunol. 4, 491-496.
  7. Kopp, E. and Medzhitov, R. (2003) Curr. Opin. Immunol. 15, 396-401.
  8. Servant, M.J. et al. (2003) J. Biol. Chem. 278, 9441-9447.

Application References

Have you published research involving the use of our products? If so we'd love to hear about it. Please let us know!

Companion Products

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

Products