Molecular cloning and characterization of an alpha1,3 fucosyltransferase, CEFT-1, from Caenorhabditis elegans

We report on the identification, molecular cloning, and characterization ofan alpha1,3 fucosyltransferase (alpha1,3FT) expressed by the nematode,Caenorhabditis elegans . Although C. elegans glycoconjugates do not expressthe Lewis x antigen Galbeta1-- >4[Fucalpha1-->3]GlcNAcbeta-->R,detergent extracts of adult C.elegans contain an alpha1,3FT that canfucosylate both nonsialylated and sialylated acceptor glycans to generatethe Lexand sialyl Lexantigens, as well as the lacdiNAc-containing acceptorGalNAcbeta1-->4GlcNAcbeta1-- >R to generate GalNAcbeta1-->4[Fucalpha1-->3]GlcNAcbeta1-->R. A search of the C.elegans genomedatabase revealed the existence of a gene with 20-23% overall identity toall five cloned human alpha1,3FTs. The putative cDNA for the C.elegansalpha1,3FT (CEFT-1) was amplified by PCR from a cDNA lambdaZAP library,cloned, and sequenced. COS7 cells transiently transfected with cDNAencoding CEFT-1 express the Lex, but not sLexantigen. The CEFT-1 in thetransfected cell extracts can synthesize Lex, but not sialyl Lex, usingexogenous acceptors. A second fucosyltransferase activity was detected inextracts of C. elegans that transfers Fuc in alpha1,2 linkage to Galspecifically on type-1 chains. The discovery of alpha-fucosyltransferasesin C. elegans opens the possibility of using this well-characterizednematode as a model system for studying the role of fucosylated glycans inthe development and survival of C.elegans and possibly other helminths.