Abstract
Summary: The cells wall of filamentous fungi in the genus Aspergillus has galactofuranose (Galf)-containing polysaccharides and glycoconjugates, including O-glycans, N-glycans, fungal-type galactomannan and glycosylinositolphosphoceramide, which are important for cell wall integrity. Here, we attempted to identify galactofuranosyltransferases that couple Galf monomers onto other wall components in Aspergillus nidulans. Using reverse-genetic and biochemical approaches, we identified that the AN8677 gene encoded a galactofuranosyltransferase, which we called GfsA, involved in Galf antigen biosynthesis. Disruption of gfsA reduced binding of β-Galf-specific antibody EB-A2 to O-glycosylated WscA protein and galactomannoproteins. The results of an in-vitroGalf antigen synthase assay revealed that GfsA has β1,5- or β1,6-galactofuranosyltransferase activity for O-glycans in glycoproteins, uses UDP-d-Galf as a sugar donor, and requires a divalent manganese cation for activity. GfsA was found to be localized at the Golgi apparatus based on cellular fractionation experiments. ΔgfsA cells exhibited an abnormal morphology characterized by poor hyphal extension, hyphal curvature and limited formation of conidia. Several gfsA orthologues were identified in members of the Pezizomycotina subphylum of Ascomycota, including the human pathogen Aspergillus fumigatus. To our knowledge, this is the first characterization of a fungal β-galactofuranosyltransferase, which was shown to be involved in Galf antigen biosynthesis of O-glycans in the Golgi. © 2013 John Wiley & Sons Ltd.
Recommended Citation
Y. Komachi and S. Hatakeyama and H. Motomatsu and T. Futagami and K. Kizjakina and P. Sobrado and K. Ekino and K. Takegawa and M. Goto and Y. Nomura and T. Oka, "GfsA Encodes a Novel Galactofuranosyltransferase Involved in Biosynthesis of Galactofuranose Antigen of O-glycan in Aspergillus Nidulans and Aspergillus Fumigatus," Molecular Microbiology, vol. 90, no. 5, pp. 1054 - 1073, Wiley, Dec 2013.
The definitive version is available at https://doi.org/10.1111/mmi.12416
Department(s)
Chemistry
Publication Status
Free Access
International Standard Serial Number (ISSN)
1365-2958; 0950-382X
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Wiley, All rights reserved.
Publication Date
01 Dec 2013
PubMed ID
24118544
Comments
National Institute of General Medical Sciences, Grant R01GM094469