Taxonomic group: fungi / Ascomycota
(Phylum: Ascomycota)
Organ / tissue: cell wall
NCBI PubMed ID: 23870253Publication DOI: 10.1016/j.bpj.2013.05.040Journal NLM ID: 0370626Publisher: Cambridge, MA: Cell Press
Correspondence: Dufrêne YF <Yves.Dufrene
uclouvain.be>, Latgé JP <Jean-paul.latge
pasteur.fr>
Institutions: Université catholique de Louvain, Institute of Life Sciences, Louvain-la-Neuve, Belgium, Unité des Aspergillus, Institut Pasteur Paris France, Paris, France, Institut National de la Santé et de la Recherche Médicale, Unité 872, Centre de Recherche des Cordeliers, Immunopathology and therapeutic immunointervention, Université Pierre et Marie Curie – Paris 6, Université Paris Descartes, Paris, France
Understanding the surface properties of the human opportunistic pathogen Aspergillus fumigatus conidia is essential given the important role they play during the fungal interactions with the human host. Although chitin synthases with myosin motor-like domain (CSM) play a major role in cell wall biosynthesis, the extent to which deletion of the CSM genes alter the surface structural and biophysical-biological properties of conidia is not fully characterized. We used three complementary atomic force microscopy techniques—i.e., structural imaging, chemical force microscopy with hydrophobic tips, and singlemolecule force spectroscopy with lectin tips—to gain detailed insights into the nanoscale surface properties (ultrastructure, hydrophobicity) and polysaccharide composition of the wild-type and the chitin synthase mutant (DcsmA, DcsmB, and ΔcsmA/csmB) conidia of A. fumigatus. Wild-type conidia were covered with a highly hydrophobic layer of rodlet nanostructures. By contrast, the surface of the ΔcsmA mutant was almost completely devoid of rodlets, leading to loss of hydrophobicity and exposure of mannan and chitin polysaccharides. The ΔcsmB and ΔcsmA/csmB mutants showed a different behavior, i.e., the surfaces featured poorly organized rodlet layers, yet with a low hydrophobicity and substantial amounts of exposed mannan and chitin at the surface. As the rodlet layer is important for masking recognition of immunogenic fungal cell wall components by innate immune cells, disappearance of rodlet layers in all three chitin synthase mutant conidia was associated with an activation of human dendritic cells. These nanoscale analyses emphasize the important and distinct roles that the CSMA and CSMB genes play in modulating the surface properties and immune interactions of A. fumigatus and demonstrate the power of atomic force microscopy in fungal genetic studies for assessing the phenotypic characteristics of mutants altered in cell surface organization.
Structure type: structural motif or average structure
Location inside paper: abstract
Trivial name: chitin
Compound class: cell wall polysaccharide, glucan, cell wall polisaccharide
Contained glycoepitopes: IEDB_135813,IEDB_137340,IEDB_141807,IEDB_151531,IEDB_153212,IEDB_241099,IEDB_423114,IEDB_423150,SB_74,SB_85
Methods: fluorescence microscopy, flow cytometry, AFM, ANOVA
Biological activity: chitin supports the resilience of cell wall
Enzymes that release or process the structure: chitin synthase enzymes(CHS)
Related record ID(s): 42643, 42648, 44855, 44856, 44877, 44889, 44899, 44913, 44915, 44917, 44923, 44925, 44940, 44941
NCBI Taxonomy refs (TaxIDs): 1266464Reference(s) to other database(s): GTC:G97099AY
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
report error