title: The DC2.3 gene in Caenorhabditis elegans encodes a galectin that recognizes the galactoseβ1→4fucose disaccharide unit.
abstract: Galectins comprise a large family of β-galactoside-binding proteins in animals and fungi. We previously isolated cDNAs of 10 galectin and galectin-like genes (lec-1 to lec-6 and lec-8 to lec-11) from Caenorhabditis elegans and characterized the carbohydrate-binding properties of their recombinant proteins. In the present study, we isolated cDNA corresponding to an open reading frame of the DC2.3a gene from C. elegans total RNA; this cDNA encodes another potential galectin. A recombinant DC2.3a protein was expressed in Escherichia coli and used for analysis. The protein displayed hemagglutinating activity against rabbit erythrocytes, bound to an asialofetuin-Sepharose column, and was eluted with lactose. Furthermore, frontal affinity chromatography (FAC) analysis confirmed that DC2.3a recognized oligosaccharides with a non-reducing terminal galactose. According to these results, we designated DC2.3 as lec-12. The carbohydrate-binding property of the recombinant DC2.3a/LEC-12a was essentially similar to that of LEC-6. Additionally, DC2.3a/LEC-12a and LEC-6 showed higher affinities for the galactoseβ1→4fucose (Galβ1→4Fuc) disaccharide than for N-acetyllactosamine. This suggests that the principal recognition unit is the Galβ1→4Fuc disaccharide as in the case of the C. elegans galectins. However, the recombinant DC2.3a/LEC-12a showed weak affinity for N-glycan E3, which was previously shown to be a preferential endogenous ligand for LEC-6. The DC2.3a/LEC-12a endogenous ligand structures appear to be somewhat different but contain the same galactose-fucose recognition motif.
authors.affiliation: Department of Biological Chemistry, School of Pharmaceutical Sciences, Teikyo University, Japan. ynsasaki@pharm.teikyo-u.ac.jp
authors.forename: Yoko
authors.initials: Y
authors.lastname: Nemoto-Sasaki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Takai
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Arata
authors.forename: Kazusa
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamada
authors.forename: Hideyo
authors.initials: H
authors.lastname: Takahashi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Natsugari
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kasai
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004187:Disaccharides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D005697:Galactosides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D037161:Galectins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008024:Ligands; D058990:Molecular Targeted Therapy; D010957:Plasmids; D011485:Protein Binding; D011817:Rabbits
chemical_list: D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D004187:Disaccharides; D005456:Fluorescent Dyes; D005697:Galactosides; D037161:Galectins; C534045:LEC-6 protein, C elegans; C525184:Lec-1 protein, C elegans; D008024:Ligands; C007816:beta-galactoside