Galactoseβ1-4fucose: A unique disaccharide unit found in N-glycans of invertebrates including nematodes.
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.
Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan.
Tomoharu
T
Takeuchi
Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan.
Yoichiro
Y
Arata
School of Pharmaceutical Sciences, Teikyo University, Tokyo, Japan.
Ken-Ichi
KI
Kasai
D000595:Amino Acid Sequence; D000818:Animals; D053898:Biosynthetic Pathways; D017173:Caenorhabditis elegans / Q000737:chemistry / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000378:metabolism; D004187:Disaccharides / Q000032:analysis* / Q000378:metabolism; D037161:Galectins / Q000737:chemistry / Q000378:metabolism*; D007448:Invertebrates / Q000737:chemistry / Q000378:metabolism; D062105:Molecular Docking Simulation; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism*; D016415:Sequence Alignment
D029742:Caenorhabditis elegans Proteins; D004187:Disaccharides; D037161:Galectins; D011134:Polysaccharides; C547518:galactopyranosyl-1-4-fucose
Caenorhabditis elegans; Galactoseβ1-4fucose; Galectin; Galβ1-4GlcNAc; Glycoproteomics; Nematode