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: Yue Pang, Rong Xiao, Xin Liu, Qingwei Li
• Journal: PloS one (PLoS One) Vol. 7 Issue 4 Pg. e35755 ( 2012) ISSN: 1932-6203 [Electronic] United States
• PMID: 22563397 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• HMGB1 Protein
• Lipopolysaccharides
• Recombinant Proteins
• Tumor Necrosis Factor-alpha
• Concanavalin A
• DNA

Topics

• Amino Acid Sequence
• Animals
• Cell Line, Tumor
• Concanavalin A (toxicity)
• DNA (metabolism)
• Gills (drug effects, metabolism)
• HMGB1 Protein (classification, genetics, metabolism)
• Humans
• Immunity, Innate
• Lampreys (metabolism)
• Lipopolysaccharides (toxicity)
• Lymphocytes (drug effects, immunology, metabolism)
• Molecular Sequence Data
• Phylogeny
• Recombinant Proteins (genetics, metabolism)
• Sequence Alignment
• Tumor Necrosis Factor-alpha (metabolism)