Mnt1, an α-(1 â 2)-mannosyltransferase responsible for the elongation of N-glycans and O-glycans in Aspergillus fumigatus.
Glycobiology
; 32(12): 1137-1152, 2022 11 22.
Article
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| MEDLINE
| ID: mdl-35871410
ABSTRACT
The fungal cell wall is necessary for survival as it serves a barrier for physical protection. Therefore, glycosyltransferases responsible for the synthesis of cell wall polysaccharides may be suitable targets for drug development. Mannose is a monosaccharide that is commonly found in sugar chains in the walls of fungi. Mannose residues are present in fungal-type galactomannan, O-glycans, N-glycans, glycosylphosphatidylinositol anchors, and glycosyl inositol phosphorylceramides in Aspergillus fumigatus. Three genes that are homologous to α-(1 â 2)-mannosyltransferase genes and belong to the glycosyltransferase family 15 were found in the A. fumigatus strain, Af293/A1163, genome cmsA/ktr4, cmsB/ktr7, and mnt1. It is reported that the mutant ∆mnt1 strain exhibited a wide range of properties that included high temperature and drug sensitivity, reduced conidia formation, leakage at the hyphal tips, and attenuation of virulence. However, it is unclear whether Mnt1 is a bona fide α-(1 â 2)-mannosyltransferase and which mannose residues are synthesized by Mnt1 in vivo. In this study, we elucidated the structure of the Mnt1 reaction product, the structure of O-glycan in the Δmnt1 strain. In addition, the length of N-glycans attached to invertase was evaluated in the Δmnt1 strain. The results indicated that Mnt1 functioned as an α-(1 â 2)-mannosyltransferase involved in the elongation of N-glycans and synthesis of the second mannose residue of O-glycans. The widespread abnormal phenotype caused by the disruption of the mnt1 gene is the combined result of the loss of mannose residues from O-glycans and N-glycans. We also clarified the enzymatic properties and substrate specificity of Mnt1 based on its predicted protein structure.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aspergillus fumigatus
/
Manosiltransferases
Idioma:
En
Revista:
Glycobiology
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Japão