RRC ID 45884
著者 Wohlschlager T, Butschi A, Grassi P, Sutov G, Gauss R, Hauck D, Schmieder SS, Knobel M, Titz A, Dell A, Haslam SM, Hengartner MO, Aebi M, Künzler M.
タイトル Methylated glycans as conserved targets of animal and fungal innate defense.
ジャーナル Proc Natl Acad Sci U S A
Abstract Effector proteins of innate immune systems recognize specific non-self epitopes. Tectonins are a family of β-propeller lectins conserved from bacteria to mammals that have been shown to bind bacterial lipopolysaccharide (LPS). We present experimental evidence that two Tectonins of fungal and animal origin have a specificity for O-methylated glycans. We show that Tectonin 2 of the mushroom Laccaria bicolor (Lb-Tec2) agglutinates Gram-negative bacteria and exerts toxicity toward the model nematode Caenorhabditis elegans, suggesting a role in fungal defense against bacteria and nematodes. Biochemical and genetic analysis of these interactions revealed that both bacterial agglutination and nematotoxicity of Lb-Tec2 depend on the recognition of methylated glycans, namely O-methylated mannose and fucose residues, as part of bacterial LPS and nematode cell-surface glycans. In addition, a C. elegans gene, termed samt-1, coding for a candidate membrane transport protein for the presumptive donor substrate of glycan methylation, S-adenosyl-methionine, from the cytoplasm to the Golgi was identified. Intriguingly, limulus lectin L6, a structurally related antibacterial protein of the Japanese horseshoe crab Tachypleus tridentatus, showed properties identical to the mushroom lectin. These results suggest that O-methylated glycans constitute a conserved target of the fungal and animal innate immune system. The broad phylogenetic distribution of O-methylated glycans increases the spectrum of potential antagonists recognized by Tectonins, rendering this conserved protein family a universal defense armor.
巻・号 111(27)
ページ E2787-96
公開日 2014-7-8
DOI 10.1073/pnas.1401176111
PII 1401176111
PMID 24879441
PMC PMC4103367
MeSH Agaricales / immunology* Amino Acid Sequence Animals Caenorhabditis elegans / immunology Horseshoe Crabs / immunology Immunity, Innate* Membrane Proteins / chemistry Membrane Proteins / metabolism Methylation Molecular Sequence Data Phylogeny Polysaccharides / metabolism* Sequence Homology, Amino Acid
IF 9.412
引用数 39
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
線虫 tm1078 tm2725 tm2530