LGP2

LGP2 (Laboratory of Genetics and Physiology 2; DHX58) is a member of the RIG-I-like receptor (RLR) family that functions as a cytosolic RNA sensor in innate antiviral immunity and participates in the detection of viral double-stranded RNA species^[1][2]. Unlike RIG-I and MDA5, LGP2 contains a conserved DExD/H-box RNA helicase domain and a C-terminal regulatory domain but lacks the N-terminal caspase recruitment domains (CARDs) required for direct downstream signal initiation, making its biological activity dependent on modulation of other RLR pathways^[1][3]. Mechanistically, LGP2 regulates RNA sensing and interferon signaling through interactions with RIG-I and MDA5, thereby influencing activation of antiviral transcriptional programs and type I interferon responses^[1][2][4]. In disease and experimental models, LGP2 has been implicated in host responses to viral infection and in cellular contexts characterized by aberrant RNA sensing, including ADAR1-deficient systems in which LGP2 is required for efficient induction of type I interferon signaling^[4]. Compared with related RLR isoforms, the absence of CARD domains represents the defining structural distinction of LGP2 and explains its role as a regulatory rather than a primary signaling receptor^[1][3]. For experimental applications, LGP2 is widely used to investigate RLR pathway regulation, RNA recognition mechanisms, and the molecular control of interferon-dependent innate immune responses^[1][4].