Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.

The mannosyltransferase Och1 is the key enzyme for synthesis of elaborated protein N-glycans in yeast. In filamentous fungi genes implicated in outer chain formation are present, but their function is unclear. In this study we have analyzed the Och1 protein of Aspergillus fumigatus. We provide first...

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Main Authors: Andrea Kotz, Johannes Wagener, Jakob Engel, Françoise H Routier, Bernd Echtenacher, Ilse Jacobsen, Jürgen Heesemann, Frank Ebel
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2010-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3012087?pdf=render
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author Andrea Kotz
Johannes Wagener
Jakob Engel
Françoise H Routier
Bernd Echtenacher
Ilse Jacobsen
Jürgen Heesemann
Frank Ebel
author_facet Andrea Kotz
Johannes Wagener
Jakob Engel
Françoise H Routier
Bernd Echtenacher
Ilse Jacobsen
Jürgen Heesemann
Frank Ebel
author_sort Andrea Kotz
collection DOAJ
description The mannosyltransferase Och1 is the key enzyme for synthesis of elaborated protein N-glycans in yeast. In filamentous fungi genes implicated in outer chain formation are present, but their function is unclear. In this study we have analyzed the Och1 protein of Aspergillus fumigatus. We provide first evidence that poly-mannosylated N-glycans exist in A. fumigatus and that their synthesis requires AfOch1 activity. This implies that AfOch1 plays a similar role as S. cerevisiae ScOch1 in the initiation of an N-glycan outer chain. A Δafoch1 mutant showed normal growth under standard and various stress conditions including elevated temperature, cell wall and oxidative stress. However, sporulation of this mutant was dramatically reduced in the presence of high calcium concentrations, suggesting that certain proteins engaged in sporulation require N-glycan outer chains to be fully functional. A characteristic feature of AfOch1 and Och1 homologues from other filamentous fungi is a signal peptide that clearly distinguishes them from their yeast counterparts. However, this difference does not appear to have consequences for its localization in the Golgi. Replacing the signal peptide of AfOch1 by a membrane anchor had no impact on its ability to complement the sporulation defect of the Δafoch1 strain. The mutant triggered a normal cytokine response in infected murine macrophages, arguing against a role of outer chains as relevant Aspergillus pathogen associated molecular patterns. Infection experiments provided no evidence for attenuation in virulence; in fact, according to our data the Δafoch1 mutant may even be slightly more virulent than the control strains.
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spelling doaj.art-908e669e996b449b8ad8a101bbf51de22022-12-22T03:42:28ZengPublic Library of Science (PLoS)PLoS ONE1932-62032010-01-01512e1572910.1371/journal.pone.0015729Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.Andrea KotzJohannes WagenerJakob EngelFrançoise H RoutierBernd EchtenacherIlse JacobsenJürgen HeesemannFrank EbelThe mannosyltransferase Och1 is the key enzyme for synthesis of elaborated protein N-glycans in yeast. In filamentous fungi genes implicated in outer chain formation are present, but their function is unclear. In this study we have analyzed the Och1 protein of Aspergillus fumigatus. We provide first evidence that poly-mannosylated N-glycans exist in A. fumigatus and that their synthesis requires AfOch1 activity. This implies that AfOch1 plays a similar role as S. cerevisiae ScOch1 in the initiation of an N-glycan outer chain. A Δafoch1 mutant showed normal growth under standard and various stress conditions including elevated temperature, cell wall and oxidative stress. However, sporulation of this mutant was dramatically reduced in the presence of high calcium concentrations, suggesting that certain proteins engaged in sporulation require N-glycan outer chains to be fully functional. A characteristic feature of AfOch1 and Och1 homologues from other filamentous fungi is a signal peptide that clearly distinguishes them from their yeast counterparts. However, this difference does not appear to have consequences for its localization in the Golgi. Replacing the signal peptide of AfOch1 by a membrane anchor had no impact on its ability to complement the sporulation defect of the Δafoch1 strain. The mutant triggered a normal cytokine response in infected murine macrophages, arguing against a role of outer chains as relevant Aspergillus pathogen associated molecular patterns. Infection experiments provided no evidence for attenuation in virulence; in fact, according to our data the Δafoch1 mutant may even be slightly more virulent than the control strains.http://europepmc.org/articles/PMC3012087?pdf=render
spellingShingle Andrea Kotz
Johannes Wagener
Jakob Engel
Françoise H Routier
Bernd Echtenacher
Ilse Jacobsen
Jürgen Heesemann
Frank Ebel
Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.
PLoS ONE
title Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.
title_full Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.
title_fullStr Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.
title_full_unstemmed Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.
title_short Approaching the secrets of N-glycosylation in Aspergillus fumigatus: characterization of the AfOch1 protein.
title_sort approaching the secrets of n glycosylation in aspergillus fumigatus characterization of the afoch1 protein
url http://europepmc.org/articles/PMC3012087?pdf=render
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