title: Evolutionary conservation of molecular structure and antiviral function of a viral receptor, LGP2, in amphioxus Branchiostoma japonicum.
abstract: RIG-I-like (where RIG-I is retinoic acid inducible gene I) receptor LGP2 (where LGP2 is laboratory of genetics and physiology) is an important intracellular receptor that recognizes viral RNAs in innate immunity, but its origin and evolution remains unknown. Here we clearly demonstrate the presence of a RIG-I-like receptor, BjLGP2, in the basal chordate amphioxus. It is predominantly expressed in the hepatic caecum and hindgut, and is upregulated following challenge with poly(I:C). BjLGP2 is distributed in the cytoplasm of both grouper spleen and flounder gill (FG) cells, and the recombinant BjLGP2 interacts with poly(I:C). BjLGP2 can enhance the expression of IFN and IFN-inducible genes in FG cells upon poly(I:C) challenge. It also significantly induces the expression of the antiviral genes ifn-i and Mx as well as the signal transduction relevant genes MAVS, NF-κB, and IRF-3 in FG cells upon lymphocystis disease virus challenge. Moreover, BjLGP2 inhibits the replication of lymphocystis disease virus in FG cells and the gene transcription of Singapore grouper iridovirus in grouper spleen cells. This is the first report showing that a LGP2 protein in invertebrate species (amphioxus) is structurally conserved and plays an antiviral role similar to that of vertebrate LGP2 proteins.
authors.affiliation: Laboratory for Evolution and Development, Department of Marine Biology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China.
authors.forename: Shousheng
authors.initials: S
authors.lastname: Liu
authors.affiliation: Laboratory for Evolution and Development, Department of Marine Biology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Laboratory for Evolution and Development, Department of Marine Biology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China.
authors.forename: Shuangshuang
authors.initials: S
authors.lastname: Yang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Youhua
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Qin
authors.affiliation: Laboratory for Evolution and Development, Department of Marine Biology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, China.
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000502:physiology*; D050838:Interferon Regulatory Factor-3 / Q000235:genetics; D064175:Lancelets / Q000737:chemistry*; D015394:Molecular Structure; D016328:NF-kappa B / Q000235:genetics; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D011991:Receptors, Virus / Q000737:chemistry*
chemical_list: D029941:Fish Proteins; D050838:Interferon Regulatory Factor-3; D016328:NF-kappa B; D011991:Receptors, Virus; D011070:Poly I-C
keywords: Amphioxus; Antiviral activity; Branchiostoma; LGP2; Lancelet