Sialyl-Tn antigen expression and O-linked GalNAc-Thr synthesis by Trypanosoma cruzi.
Most Trypanosoma cruzi O-glycans are linked to Thr/Ser residues via N-acetylglucosamine. We report that the mucin-type carcinoma-associated sialyl-Tn antigen (NeuAc-GalNAc-O-Ser/Thr) is expressed by T. cruzi. A specific MAb allowed us to localize the antigen on the surface of epimastigotes and to identify reactive components in parasite lysates (32, 60, and 94kDa). In addition, ppGalNAc-T activity was characterized in epimastigotes, and direct evidence was obtained for the in vitro incorporation of GalNAc to a synthetic peptide derived from a T. cruzi mucin. These results add an as yet unknown complexity to the pathways of O-glycan biosynthesis in this protozoan parasite.
Freire
Teresa
T
Depto. de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
Robello
Carlos
C
Soulé
Silvia
S
Ferreira
Fernando
F
Osinaga
Eduardo
E
D000116:Acetylgalactosamine / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D019085:Fluorescent Antibody Technique, Direct / Q000379:methods; D006863:Hydrogen-Ion Concentration; D008666:Metalloendopeptidases; D008969:Molecular Sequence Data; D009077:Mucins / Q000737:chemistry / Q000378:metabolism*; D017350:N-Acetylgalactosaminyltransferases / Q000737:chemistry / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000737:chemistry / Q000378:metabolism*
D015295:Antigens, Tumor-Associated, Carbohydrate; D009077:Mucins; C040286:Tn antigen; C055491:sialosyl-Tn antigen; D017350:N-Acetylgalactosaminyltransferases; C416226:UDP-GalNAc polypeptide N-acetylgalactosaminyltransferase 9; D008666:Metalloendopeptidases; C477817:molecule metalloprotease-related protein-1, human; D000116:Acetylgalactosamine