title: Crosstalk between ABO and Forssman (FORS) blood group systems: FORS1 antigen synthesis by ABO gene-encoded glycosyltransferases.
abstract: A and B alleles at the ABO genetic locus specify A and B glycosyltransferases that catalyze the biosynthesis of A and B oligosaccharide antigens, respectively, of blood group ABO system which is important in transfusion and transplantation medicine. GBGT1 gene encodes Forssman glycolipid synthase (FS), another glycosyltransferase that produces Forssman antigen (FORS1). Humans are considered to be Forssman antigen-negative species without functional FS. However, rare individuals exhibiting Apaephenotype carry a dominant active GBGT1 gene and express Forssman antigen on RBCs. Accordingly, FORS system was recognized as the 31st blood group system. Mouse ABO gene encodes a cis-AB transferase capable of producing both A and B antigens. This murine enzyme contains the same GlyGlyAla tripeptide sequence as FSs at the position important for the determination of sugar specificity. We, therefore, transfected the expression construct into appropriate recipient cells and examined whether mouse cis-AB transferase may also exhibit FS activity. The result was positive, confirming the crosstalk between the ABO and FORS systems. Further experiments have revealed that the introduction of this tripeptide sequence to human A transferase conferred some, although weak, FS activity, suggesting that it is also involved in the recognition/binding of acceptor substrates, in addition to donor nucleotide-sugars.
authors.affiliation: Laboratory of Immunohematology and Glycobiology, Josep Carreras Leukaemia Research Institute (IJC), Campus Can Ruti, Badalona, Barcelona, Spain.
authors.forename: Miyako
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Laboratory of Immunohematology and Glycobiology, Josep Carreras Leukaemia Research Institute (IJC), Campus Can Ruti, Badalona, Barcelona, Spain.
authors.forename: Emili
authors.initials: E
authors.lastname: Cid
authors.affiliation: Laboratory of Immunohematology and Glycobiology, Josep Carreras Leukaemia Research Institute (IJC), Campus Can Ruti, Badalona, Barcelona, Spain.|Programa de Medicina Predictiva i Personalitzada del Càncer (PMPPC), Institut d'Investigació Germans Trias i Pujol (IGTP), Campus Can Ruti, Badalona, Barcelona, Spain.
authors.forename: Fumiichiro
authors.initials: F
authors.lastname: Yamamoto
mesh_terms: D000017:ABO Blood-Group System / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000483:Alleles; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D017124:Conserved Sequence; D005577:Forssman Antigen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009154:Mutation; D017350:N-Acetylgalactosaminyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010641:Phenotype
chemical_list: D000017:ABO Blood-Group System; D005577:Forssman Antigen; D017350:N-Acetylgalactosaminyltransferases; C023216:globoside alpha-N-acetylgalactosaminyltransferase