Cell Signaling Technology

Product Pathways - NF-kB Signaling

Rig-I Antibody #4520

Applications Reactivity Sensitivity MW (kDa) Source
W H M (Mk) Endogenous 102 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  M=Mouse  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

Rig-I Antibody detects endogenous levels of total Rig-I protein.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues at the carboxyl terminus of human Rig-I. Antibodies were purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells, mock transfected or transfected with Rig-I, and from differentiated THP-1 cells, untreated or treated with LPS, using Rig-I Antibody.

Background

Antiviral innate immunity depends on the combination of parallel pathways triggered by virus detecting proteins in the Toll-like receptor (TLR) family and RNA helicases, such as Rig-I (retinoic acid-inducible gene I) and MDA-5 (melanoma differentiation-associated antigen 5), which promote the transcription of type I interferons (IFN) and antiviral enzymes (1-3). TLRs and helicase proteins contain sites that recognize the molecular patterns of different virus types, including DNA, single-stranded RNA (ssRNA), double-stranded RNA (dsRNA), and glycoproteins. These antiviral proteins are found in different cell compartments; TLRs (i.e. TLR3, TLR7, TLR8, and TLR9) are expressed on endosomal membranes and helicases are localized to the cytoplasm. Rig-I expression is induced by retinoic acid, LPS, IFN, and viral infection (4,5). Both Rig-I and MDA-5 share a DExD/H-box helicase domain that detects viral dsRNA and two amino-terminal caspase recruitment domains (CARD) that are required for triggering downstream signaling (4-7). Rig-I binds both dsRNA and viral ssRNA that contains a 5'-triphosphate end not seen in host RNA (8,9). Though structurally related, Rig-I and MDA-5 detect a distinct set of viruses (10,11). The CARD domain of the helicases, which is sufficient to generate signaling and IFN production, is recruited to the CARD domain of the MAVS/VISA/Cardif/IPS-1 mitochondrial protein, which triggers activation of NF-κB, TBK1/IKKε, and IRF-3/IRF-7 (12-15).

  1. Yoneyama, M. and Fujita, T. (2007) J Biol Chem 282, 15315-8.
  2. Meylan, E. and Tschopp, J. (2006) Mol Cell 22, 561-9.
  3. Thompson, A.J. and Locarnini, S.A. (2007) Immunol Cell Biol 85, 435-45.
  4. Imaizumi, T. et al. (2002) Biochem Biophys Res Commun 292, 274-9.
  5. Zhang, X. et al. (2000) Microb Pathog 28, 267-78.
  6. Yoneyama, M. et al. (2005) J Immunol 175, 2851-8.
  7. Yoneyama, M. et al. (2004) Nat Immunol 5, 730-7.
  8. Hornung, V. et al. (2006) Science 314, 994-7.
  9. Pichlmair, A. et al. (2006) Science 314, 997-1001.
  10. Kato, H. et al. (2006) Nature 441, 101-5.
  11. Childs, K. et al. (2007) Virology 359, 190-200.
  12. Meylan, E. et al. (2005) Nature 437, 1167-72.
  13. Xu, L.G. et al. (2005) Mol Cell 19, 727-40.
  14. Kawai, T. et al. (2005) Nat Immunol 6, 981-8.
  15. Seth, R.B. et al. (2005) Cell 122, 669-82.

Application References

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

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