MDA-5 (D74E4) Rabbit mAb

5321:

Immunoprecipitation , Western Blotting

MDA-5 (D74E4) Rabbit mAb detects endogenous levels of total MDA-5 protein.

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Arg470 of human MDA-5.

Western Blotting

Western blot analysis of extracts from 293T cells, mock transfected (-) or transfected with human MDA-5 (+), using MDA-5 (D74E4) Rabbit mAb.

Western Blotting

Western blot anlaysis of extracts from differentiated THP-1 cells, untreated or treated with LPS (1 μg/ml, indicated times), using MDA-5 (D74E4) Rabbit mAb.

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).

MDA-5 (16,17), also named Ifih1 (interferon induced with helicase C domain 1), RH116 (RNA helicase-DEAD box protein 116) (18), or Helicard (19) is found to be induced by interferon. During apoptosis, MDA-5 is cleaved by caspases, separating the helicase and CARD domains (19). MDA-5 is uniquely activated by picornavirus (20) and measles virus (21).

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.
16. Kang, D.C. et al. (2002) Proc Natl Acad Sci U S A 99, 637-42.
17. Kang, D.C. et al. (2004) Oncogene 23, 1789-800.
18. Cocude, C. et al. (2003) J Gen Virol 84, 3215-25.
19. Kovacsovics, M. et al. (2002) Curr Biol 12, 838-43.
20. Kato, H. et al. (2006) Nature 441, 101-5.
21. Berghäll, H. et al. (2006) Microbes Infect 8, 2138-44.

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

• 3743 Rig-I (D14G6) Rabbit mAb
• 4200 Rig-I (D33H10) Rabbit mAb
• 7071 Phototope^® -HRP Western Blot Detection System, Anti-rabbit IgG, HRP-linked Antibody
• 7074 Anti-rabbit IgG, HRP-linked Antibody
• 7720 Prestained Protein Marker, Broad Range (Premixed Format)
• 7727 Biotinylated Protein Ladder Detection Pack
• 7003 20X LumiGLO^® Reagent and 20X Peroxide
• 4110 MDA-5 (R470) Antibody

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