Evidence for glycosylation-dependent activities of polypeptide N-acetylgalactosaminyltransferases rGalNAc-T2 and-T4 on mucin glycopeptides

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

Hanisch, FG (Autor) Outra; Celso Reis (Autor) Outra; Clausen, H (Autor) Outra; Paulsen, H (Autor) Outra

Revista

Título: Glycobiology

Vol. 11

Páginas: 731-740

ISSN: 0959-6658

Editora: Oxford University Press

Indexação

ISI Web of Knowledge - 61 Citações

Scopus - 61 Citações

Outras Informações

ID Authenticus: P-008-NPE

DOI: 10.1093/glycob/11.9.731

Abstract (EN): We present evidence that site-specific O-glycosylation by recombinant polypeptide N-acetylgalactosaminyltransferases rGalNAc-T2 and -T4 is controlled by the primary sequence context, as well as by the position and structure of previously introduced O-glycans. Synthetic mucin-type (glyco)peptides corresponding to sections of the tandem repeat regions of MUC1, MUC2, and MUC4 were used as substrates for recombinant polypeptide N-acetylgalactosaminyltransferases, rGalNAc-T2 and -T4. By concerted and sequential action the two transferases are able to fully glycosylate MUC1 but only partially MUC2 and MUC4 tandem repeat peptides. GalNAc residues on MUC1 acceptor peptides trigger activity of rGalNAc-T4 directed to Ser in VTSA and Thr in PDTR and of rGalNAc-T2 to Ser/Thr within the GSTA motif of variant MUC1 peptides. However, elongation of GalNAc by beta3-galactosylation inhibits rGalNAc-T4 activity completely and rGalNAc-T2 activity with respect to the acceptor site GSTA. These findings are in accord with the inhibition of rGalNAc-T2 and -T4 by fully GalNAc-substituted MUC1 repeat peptide and support a glycosylation-dependent activity induction or enhancement of both enzymes.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10