Cell Signaling Technology
XP Monoclonal Antibody

Product Pathways - NF-kB Signaling

IRF-3 (D6I4C) XP® Rabbit mAb #11904

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP IF-IC H Mk Endogenous 50-55 Rabbit IgG

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  IF-IC=Immunofluorescence (Immunocytochemistry)
Reactivity Key:  H=Human  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

IRF-3 (D6I4C) XP® Rabbit mAb recognizes endogenous levels of total IRF-3 protein.

Source / Purification

Monoclonal antibody is produced by immunizing animals with recombinant human IRF-3 protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from various cell lines using IRF-3 (D6I4C) XP® Rabbit mAb.

IP

IP

Immunoprecipitation of IRF-3 from THP-1 cell extracts using Rabbit (DA1E) mAb IgG XP® Isotype Control #3900 (lane 2) or IRF-3 (D6I4C) XP® Rabbit mAb (lane 3). Lane 1 is 10% input. Western blot analysis was performed using IRF-3 (D6I4C) XP® Rabbit mAb. Mouse Anti-rabbit IgG (Conformation Specific) (L27A9) mAb #3678 and Anti-mouse IgG, HRP-linked Antibody #7076 were used as secondary antibodies.

IF-IC

IF-IC

Confocal immunofluorescent analysis of HT-29 cells, untransfected (left) or transfected with Poly(I:C) (2.5 μg/ml, 6 hr; right), using IRF-3 (D6I4C) XP® Rabbit mAb (green). Blue pseudocolor = DRAQ5® #4084 (fluorescent DNA dye).


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 Ser and Thr 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 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, 15272-8.
  5. Yoneyama, M. et al. (2002) J Interferon Cytokine Res 22, 73-6.
  6. Fitzgerald, K.A. et al. (2003) Nat Immunol 4, 491-6.
  7. Kopp, E. and Medzhitov, R. (2003) Curr Opin Immunol 15, 396-401.
  8. Servant, M.J. et al. (2003) J Biol Chem 278, 9441-7.

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