InvivoGen offers HEK RLR reporter cells to study the role of RIG-I and MDA5.
RIG-I (retinoic-acid-inducible protein 1, also known as Ddx58) and MDA-5 (melanoma-differentiation-associated gene 5, also known as Ifih1 or Helicard) are cytoplasmic RNA helicases that belong to the RIG-I-like receptors (RLRs) family and are critical for host antiviral responses[1].
RIG-I and MDA-5 sense double-stranded RNA (dsRNA), a replication intermediate for RNA viruses, and signal through the mitochondrial antiviral signaling protein MAVS (also known as IPS-1, VISA, or Cardif), leading to the production of type-I interferons (IFN-α and IFN-β)[2]. LGP2 is the third member of the RLR family: it binds RNA but has no signaling activity, and thus acts as a negative feedback regulator of RIG-I and MDA-5.
References:
1. Gebhardt A. et al., 2017. Discrimination of self and non-self ribonucleic acids. Journal of Interferons & Cytokine Research. 37: 184-97.
2. Yoneyama M. et al., 2015. Viral RNA detection by RIG-I-like receptors. Curr Opin Immunol. 32: 48-53.