Caenorhabditis elegans N-glycan Core β-galactoside Confers Sensitivity towards Nematotoxic Fungal Galectin CGL2

PLoS Pathogens

Peter H. Seeberger¹  Xiaoqiang Guo¹  Iain B. H. Wilson²  Katharina Paschinger²  Martin A. Wälti³  Markus Künzler³  Markus Aebi³  Alexander Titz³  Alex Butschi⁴  Michael O. Hengartner⁴  Vincent Olieric⁵  Katharina Nöbauer⁶ 

[1] Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland;Department of Chemistry, University of Natural Resources and Applied Life Sciences (BOKU), Vienna, Austria;Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland;Institute of Molecular Biology, University of Zürich, Zürich, Switzerland;Swiss Light Source (SLS), Paul-Scherrer-Institute (PSI), Villigen, Switzerland;VetOMICS Core Facility for Proteomics & Metabolomics Studies, University of Veterinary Medicine, Vienna, Austria

关键词: Caenorhabditis elegans;    Lectins;    Toxicity;    Gastrointestinal tract;    Biosynthesis;    Fungal structure;    Fungi;    Larvae;   

DOI  :  10.1371/journal.ppat.1000717

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The physiological role of fungal galectins has remained elusive. Here, we show that feeding of a mushroom galectin, Coprinopsis cinerea CGL2, to Caenorhabditis elegans inhibited development and reproduction and ultimately resulted in killing of this nematode. The lack of toxicity of a carbohydrate-binding defective CGL2 variant and the resistance of a C. elegans mutant defective in GDP-fucose biosynthesis suggested that CGL2-mediated nematotoxicity depends on the interaction between the galectin and a fucose-containing glycoconjugate. A screen for CGL2-resistant worm mutants identified this glycoconjugate as a Galβ1,4Fucα1,6 modification of C. elegans N-glycan cores. Analysis of N-glycan structures in wild type and CGL2-resistant nematodes confirmed this finding and allowed the identification of a novel putative glycosyltransferase required for the biosynthesis of this glycoepitope. The X-ray crystal structure of a complex between CGL2 and the Galβ1,4Fucα1,6GlcNAc trisaccharide at 1.5 Å resolution revealed the biophysical basis for this interaction. Our results suggest that fungal galectins play a role in the defense of fungi against predators by binding to specific glycoconjugates of these organisms.

【 授权许可】

CC BY