Purified EDEM3 or EDEM1 alone produces determinant oligosaccharide structures from M8B in mammalian glycoprotein ERAD.
Elife
; 102021 10 26.
Article
em En
| MEDLINE
| ID: mdl-34698634
ABSTRACT
Sequential mannose trimming of N-glycan, from M9 to M8B and then to oligosaccharides exposing the α1,6-linked mannosyl residue (M7A, M6, and M5), facilitates endoplasmic reticulum-associated degradation of misfolded glycoproteins (gpERAD). We previously showed that EDEM2 stably disulfide-bonded to the thioredoxin domain-containing protein TXNDC11 is responsible for the first step (George et al., 2020). Here, we show that EDEM3 and EDEM1 are responsible for the second step. Incubation of pyridylamine-labeled M8B with purified EDEM3 alone produced M7 (M7A and M7C), M6, and M5. EDEM1 showed a similar tendency, although much lower amounts of M6 and M5 were produced. Thus, EDEM3 is a major α1,2-mannosidase for the second step from M8B. Both EDEM3 and EDEM1 trimmed M8B from a glycoprotein efficiently. Our confirmation of the Golgi localization of MAN1B indicates that no other α1,2-mannosidase is required for gpERAD. Accordingly, we have established the entire route of oligosaccharide processing and the enzymes responsible.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oligossacarídeos
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Proteínas de Ligação ao Cálcio
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Glicoproteínas
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Alfa-Manosidase
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Degradação Associada com o Retículo Endoplasmático
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Proteínas de Membrana
Limite:
Humans
Idioma:
En
Revista:
Elife
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Japão