title: Identification and characterization of the lamprey high-mobility group box 1 gene.
abstract: High-mobility group box 1 (HMGB1), a highly conserved DNA-binding protein, plays an important role in maintaining nucleosome structures, transcription, and inflammation. We identified a homolog of HMGB1 in the Japanese lamprey (Lampetra japonica). The Lampetra japonica HMGB1 gene (Lj-HMGB1) has over 70% sequence identity with its homologs in jawed vertebrates. Despite the reasonably high sequence identity with other HMGB1 proteins, Lj-HMGB1 did not group together with these proteins in a phylogenetic analysis. We examined Lj-HMGB1 expression in lymphocyte-like cells, and the kidneys, heart, gills, and intestines of lampreys before and after the animals were challenged with lipopolysaccharide (LPS) and concanavalin A (ConA). Lj-HMGB1 was initially expressed at a higher level in the heart, but after treatment with LPS and ConA only the gills demonstrated a significant up-regulation of expression. The recombinant Lj-HMGB1 (rLj-HMGB1) protein bound double-stranded DNA and induced the proliferation of human adenocarcinoma cells to a similar extent as human HMGB1. We further revealed that Lj-HMGB1 was able to induce the production of tumor necrosis factor-α (TNF-α), a pro-inflammatory mediator, in activated human acute monocytic leukemia cells. These results suggest that lampreys use HMGB1 to activate their innate immunity for the purpose of pathogen defense.
authors.affiliation: Institute of Marine Genomics and Proteomics, Liaoning Normal University, Dalian, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Pang
authors.forename: Rong
authors.initials: R
authors.lastname: Xiao
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D003208:Concanavalin A / Q000633:toxicity; D004247:DNA / Q000378:metabolism; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D024243:HMGB1 Protein / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007113:Immunity, Innate; D007798:Lampreys / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D024243:HMGB1 Protein; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003208:Concanavalin A; D004247:DNA