Protein glycosylation mutants of procyclic Trypanosoma brucei: defects in the asparagine-glycosylation pathway.
Glycobiology
; 9(2): 181-90, 1999 Feb.
Article
em En
| MEDLINE
| ID: mdl-9949195
ABSTRACT
We employed a genetic approach to study protein glycosylation in the procyclic form of the parasite Trypanosoma brucei. Two different mutant parasites, ConA 1-1 and ConA 4-1, were isolated from mutagenized cultures by selecting cells which resisted killing or agglutination by concanavalin A. Both mutant cells show reduced concanavalin A binding. However, the mutants have different phenotypes, as indicated by the fact that ConA 1-1 binds to wheat germ agglutinin but ConA 4-1 and wild type do not. A blot probed with concanavalin A revealed that many proteins in both mutants lost the ability to bind this lectin, and the blots resembled one of wild type membrane proteins treated with PNGase F. This finding suggested that the mutants had altered asparagine-linked glycosylation. This conclusion was confirmed by studies on a flagellar protein (Fla1) and procyclic acidic repetitive protein (PARP). Structural analysis indicated that the N- glycan of wild type PARP is exclusively Man5GlcNAc2 whereas that in both mutants is predominantly a hybrid type with a terminal N- acetyllactosamine. The occupancy of the PARP glycosylation site in ConA 4-1 was much lower than that in ConA 1-1. These mutants will be useful for studying trypanosome glycosylation mechanisms and function.
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Base de dados:
MEDLINE
Assunto principal:
Asparagina
/
Trypanosoma brucei brucei
/
Proteínas de Protozoários
/
Processamento de Proteína Pós-Traducional
/
Mutação
Limite:
Animals
Idioma:
En
Revista:
Glycobiology
Assunto da revista:
BIOQUIMICA
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Estados Unidos