| First Author | Satoh T | Year | 2010 |
| Journal | Proc Natl Acad Sci U S A | Volume | 107 |
| Issue | 4 | Pages | 1512-7 |
| PubMed ID | 20080593 | Mgi Jnum | J:156867 |
| Mgi Id | MGI:4421606 | Doi | 10.1073/pnas.0912986107 |
| Citation | Satoh T, et al. (2010) LGP2 is a positive regulator of RIG-I- and MDA5-mediated antiviral responses. Proc Natl Acad Sci U S A 107(4):1512-7 |
| abstractText | RNA virus infection is recognized by retinoic acid-inducible gene (RIG)-I-like receptors (RLRs), RIG-I, and melanoma differentiation-associated gene 5 (MDA5) in the cytoplasm. RLRs are comprised of N-terminal caspase-recruitment domains (CARDs) and a DExD/H-box helicase domain. The third member of the RLR family, LGP2, lacks any CARDs and was originally identified as a negative regulator of RLR signaling. In the present study, we generated mice lacking LGP2 and found that LGP2 was required for RIG-I- and MDA5-mediated antiviral responses. In particular, LGP2 was essential for type I IFN production in response to picornaviridae infection. Overexpression of the CARDs from RIG-I and MDA5 in Lgp2 (-/-) fibroblasts activated the IFN-beta promoter, suggesting that LGP2 acts upstream of RIG-I and MDA5. We further examined the role of the LGP2 helicase domain by generating mice harboring a point mutation of Lys-30 to Ala (Lgp2 (K30A/K30A)) that abrogated the LGP2 ATPase activity. Lgp2 (K30A/K30A) dendritic cells showed impaired IFN-beta productions in response to various RNA viruses to extents similar to those of Lgp2 (-/-) cells. Lgp2 (-/-) and Lgp2 (K30A/K30A) mice were highly susceptible to encephalomyocarditis virus infection. Nevertheless, LGP2 and its ATPase activity were dispensable for the responses to synthetic RNA ligands for MDA5 and RIG-I. Taken together, the present data suggest that LGP2 facilitates viral RNA recognition by RIG-I and MDA5 through its ATPase domain. |
