LGP2 Protein, Human (HEK293, FLAG)

LGP2 Protein functions as a key regulator of RIGI and IFIH1/MDA5-mediated antiviral signaling, contributing both negative and positive regulatory functions that are contingent on various factors such as the infecting virus, target cells, or a combination of both. Lacking the CARD domain necessary for activating MAVS/IPS1-dependent signaling events, LGP2 cannot initiate antiviral signaling on its own. Its inhibitory effects on RIG-I signaling may involve multiple mechanisms, including competition with RIGI for binding to viral RNA, direct binding to RIGI to impede dimerization and interaction with MAVS/IPS1, and competition with IKBKE for binding to MAVS/IPS1, thereby hindering IRF3 activation. Conversely, its positive regulatory role may encompass activities such as unwinding or stripping nucleoproteins from viral RNA, thereby facilitating recognition by RIGI and IFIH1/MDA5. LGP2 plays a crucial role in the innate immune response to various RNA viruses, DNA viruses like poxviruses and coronavirus SARS-CoV-2, as well as the bacterial pathogen Listeria monocytogenes, highlighting its versatile involvement in antiviral defense. The protein exhibits affinity for both single-stranded and double-stranded RNA, with a preference for 5'-triphosphorylated RNA, although it can recognize RNA lacking this modification.