Cloning and expression of a novel, tissue specifically expressed member of the UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase family.
J Biol Chem
; 273(42): 27749-54, 1998 Oct 16.
Article
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| MEDLINE
| ID: mdl-9765313
We report the cloning and expression of the fifth member of the mammalian UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (ppGaNTase) family. Degenerate polymerase chain reaction amplification and hybridization screening of a rat sublingual gland (RSLG) cDNA library were used to identify a novel isoform termed ppGaNTase-T5. Conceptual translation of the cDNA reveals a uniquely long stem region not observed for other members of this enzyme family. Recombinant proteins expressed transiently in COS7 cells displayed transferase activity in vitro. Relative activity and substrate preferences of ppGaNTase-T5 were compared with previously identified isoforms (ppGaNTase-T1, -T3, and -T4); ppGaNTase-T5 and -T4 glycosylated a restricted subset of peptides whereas ppGaNTase-T1 and -T3 glycosylated a broader range of substrates. Northern blot analysis revealed that ppGaNTase-T5 is expressed in a highly tissue-specific manner; abundant expression was seen in the RSLG, with lesser amounts of message in the stomach, small intestine, and colon. Therefore, the pattern of expression of ppGaNTase-T5 is the most restricted of all isoforms examined thus far. The identification of this novel isoform underscores the diversity and complexity of the family of genes controlling O-linked glycosylation.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
N-Acetilgalactosaminiltransferasas
/
Isoenzimas
Límite:
Animals
Idioma:
En
Revista:
J Biol Chem
Año:
1998
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos