The lectin domain of UDP-N-acetyl-D-galactosamine : polypeptide N-acetylgalactosaminyltransferase-T4 directs its glycopeptide specificities

• Tipo: Artigo em Revista Científica Internacional
• Data: 2000

Autores

Hassan, H (Autor) Outra; Celso Reis (Autor) Outra; Bennett, EP (Autor) Outra; Mirgorodskaya, E (Autor) Outra; Roepstorff, P (Autor) Outra; Hollingsworth, MA (Autor) Outra; Burchell, J (Autor) Outra; Taylor Papadimitriou, J (Autor) Outra; Clausen, H (Autor) Outra

Revista

Título: Journal of Biological Chemistry

Vol. 275

Páginas: 38197-38205

ISSN: 0021-9258

Editora: Elsevier

Indexação

ISI Web of Knowledge - 131 Citações

Scopus - 136 Citações

Outras Informações

ID Authenticus: P-000-Y6X

DOI: 10.1074/jbc.m005783200

Abstract (EN): The initiation step of mucin-type O-glycosylation is controlled by a large family of homologous UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferases (GalNAc-transferases), Differences in kinetic properties, substrate specificities, and expression patterns of these isoenzymes provide for differential regulation of O-glycan attachment sites and density, Recently, it has emerged that some GalNAc-transferase isoforms in, vitro selectively function with partially GalNAc O-glycosylated acceptor peptides rather than with the corresponding unglycosylated peptides, O-Glycan attachment to selected sites, most notably two sites in the MUC1 tandem repeat, is entirely dependent on the glycosylation-dependent function of GalNAc-T4. Here we present data that a putative lectin domain found in the C terminus of GalNAc-T4 functions as a GalNAc lectin and confers its glycopeptide specificity. A single amino acid substitution in the lectin domain of a secreted form of GalNAc-T4 selectively blocked GalNAc-glycopeptide activity, while the general activity to peptides exerted by this enzyme was unaffected. Furthermore, the GalNAc-glycopeptide activity of wild-type secreted GalNAc-T4 was selectively inhibited by free GalNAc, while the activity with peptides was unaffected.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9