Molecular cloning and characterization of an α1,3 fucosyltransferase, CEFT-1, from Caenorhabditis elegans

We report on the identification, molecular cloning, and characterization of an alpha 1,3 fucosyltransferase (alpha 1,3FT) expressed by the nematode, Caenorhabditis elegans, Although C. elegans glycoconjugates do not express the Lewis x antigen Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta-->R, detergent extracts of adult C,elegans contain an al,3FT that can fucosylate both nonsialylated and sialylated acceptor glycans to generate the Le(X) and sialyl Le(X) antigens, as well as the lacdiNAc-containing acceptor GalNAc beta 1-->4GlcNAc beta 1-->R to generate GalNAc beta 1-->4 [Fuc alpha 1-->3]GlcNAc beta 1-->R. A search of the C. elegans genome database revealed the existence of a gene with 20-23% overall identity to all five cloned human alpha 1,3FTs. The putative cDNA for the C,elegans alpha 1,3FT (CEFT-1) was amplified by PCR from a cDNA lambda ZAP library, cloned, and sequenced. COS7 cells transiently transfected with cDNA encoding CEFT-1 express the Le(X), but not sLe(X) antigen. The CEFT-1 in the transfected cell extracts can synthesize Le(X), but not sialyl Le(X), using exogenous accepters. A second fucosyltransferase activity was detected in extracts of C,elegans that transfers Fuc in alpha 1,2 linkage to Gal specifically on type-1 chains. The discovery of alpha-fucosyltransferases in C. elegans opens the possibility of using this well-characterized nematode as a model system for studying the role of fucosylated glycans in the development and survival of C,elegans and possibly other helminths.