Galactoseβ1-4fucose: A unique disaccharide unit found in N-glycans of invertebrates including nematodes

• Published in: Proteomics (Weinheim) Vol. 16; no. 24; pp. 3137 - 3147
• Main Authors: Takeuchi, Tomoharu, Arata, Yoichiro, Kasai, Ken-ichi
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 01.12.2016; Wiley Subscription Services, Inc
• Subjects: Amino Acid Sequence; Animals; Biosynthetic Pathways; Caenorhabditis elegans; Caenorhabditis elegans - chemistry; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - chemistry; Caenorhabditis elegans Proteins - metabolism; Disaccharides; Disaccharides - analysis; Disaccharides - metabolism; Epitopes; Fungi; Galactoseβ1-4fucose; Galectin; Galectins - chemistry; Galectins - metabolism; Galβ1-4GlcNAc; Glycan; Glycoproteomics; Invertebrates; Invertebrates - chemistry; Invertebrates - metabolism; Ligands; Molecular Docking Simulation; Nematode; Nematodes; Parasitic diseases; Polysaccharides; Polysaccharides - chemistry; Polysaccharides - metabolism; Proteins; Protostomia; Sequence Alignment; Target recognition; Tuning; Vertebrates; Galectin; Caenorhabditis elegans; Nematode; Glycoproteomics; Galβ1-4GlcNAc; Galactoseβ1-4fucose
• ISSN: 1615-9853; 1615-9861
• DOI: 10.1002/pmic.201600001

Galactoseβ1‐4fucose (Galβ1‐4Fuc), a unique disaccharide unit found only on the N‐glycans of Protostomia, has been intensively studied, particularly in Nematoda. Galβ1‐4Fuc attached to the 6‐OH of the innermost GlcNAc of N‐glycans has been identified as an endogenous target recognized by Caenorhabditis elegans galectin LEC‐6 and might function as an endogenous ligand for other galectins as well. Interactions between galectins and N‐glycans might be subject to fine‐tuning through modifications of the penultimate GlcNAc and the Galβ1‐4Fuc unit. Similar fine‐tuning is also observable in vertebrate galectins, although their major recognition unit is a Galβ1‐4GlcNAc. In Protostomia, it can be postulated that glycan‐binding proteins and their ligands have coevolved; however, epitopes such as Galβ1‐4Fuc were then hijacked as targets by other organisms. Fungal (Coprinopsis cinerea) galectin 2, CGL2, binds the Galβ1‐4Fuc on C. elegans glycans to exert its nematotoxicity. Some human and mouse galectins bind to synthesized Galβ1‐4Fuc; as some parasitic nematodes express this motif, its recognition by mammalian galectins could hypothetically be involved in host defense, similar to fungal CGL2. In this review, we discuss the Galβ1‐4Fuc unit in Protostomia as a possible equivalent for the Galβ1‐4GlcNAc unit in vertebrates and a potential non‐self glycomarker useful for pathogen recognition.