GH16 and GH81 family β-(1,3)-glucanases in Aspergillus fumigatus are essential for conidial cell wall morphogenesis.
The fungal cell wall is a rigid structure because of fibrillar and branched β-(1,3)-glucan linked to chitin. Softening of the cell wall is an essential phenomenon during fungal morphogenesis, wherein rigid cell wall structures are cleaved by glycosylhydrolases. During the search for glycosylhydrolases acting on β-(1,3)-glucan, we identified seven genes in the Aspergillus fumigatus genome coding for potential endo-β-(1,3)-glucanase. ENG1 (previously characterized and named ENGL1, Mouyna et al., ), belongs to the Glycoside-Hydrolase 81 (GH81) family, while ENG2 to ENG7, to GH16 family. ENG1 and four GH16 genes (ENG2-5) were expressed in the resting conidia as well as during germination, suggesting an essential role during A. fumigatus morphogenesis. Here, we report the effect of sequential deletion of AfENG2-5 (GH16) followed by AfENG1 (GH81) deletion in the Δeng2,3,4,5 mutant. The Δeng1,2,3,4,5 mutant showed conidial defects, with linear chains of conidia unable to separate while the germination rate was not affected. These results show, for the first time in a filamentous fungus, that endo β-(1,3)-glucanases are essential for proper conidial cell wall assembly and thus segregation of conidia during conidiation.
Unité des Aspergillus, Département de Mycologie, France.
Isabelle
I
Mouyna
Unité des Aspergillus, Département de Mycologie, France.
Vishukumar
V
Aimanianda
Unité des Aspergillus, Département de Mycologie, France.|Microsynth Austria Leberstrasse, 20 1110, Vienna, Austria.
Lukas
L
Hartl
Plateforme UltraPole, France.
Marie-Christine
MC
Prevost
Transcriptome and EpiGenome Platform, Institut Pasteur, 25-28 rue du Docteur Roux, 75724, Paris Cedex 15, France.
Odile
O
Sismeiro
Transcriptome and EpiGenome Platform, Institut Pasteur, 25-28 rue du Docteur Roux, 75724, Paris Cedex 15, France.
Marie-Agnès
MA
Dillies
Transcriptome and EpiGenome Platform, Institut Pasteur, 25-28 rue du Docteur Roux, 75724, Paris Cedex 15, France.
Bernd
B
Jagla
Transcriptome and EpiGenome Platform, Institut Pasteur, 25-28 rue du Docteur Roux, 75724, Paris Cedex 15, France.
Rachel
R
Legendre
Transcriptome and EpiGenome Platform, Institut Pasteur, 25-28 rue du Docteur Roux, 75724, Paris Cedex 15, France.
Jean-Yves
JY
Coppee
Unité des Aspergillus, Département de Mycologie, France.
Jean-Paul
JP
Latgé
D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000254:growth & development / Q000648:ultrastructure; D002236:Carbohydrate Conformation; D002473:Cell Wall / Q000201:enzymology* / Q000648:ultrastructure; D005656:Fungal Proteins / Q000502:physiology*; D006026:Glycoside Hydrolases / Q000502:physiology*; D006031:Glycosylation; D009024:Morphogenesis; D013172:Spores, Fungal / Q000201:enzymology* / Q000254:growth & development / Q000648:ultrastructure
D005656:Fungal Proteins; D006026:Glycoside Hydrolases