Scalar nanostructure of the
| Autor: | Megan D, Lenardon, Prashant, Sood, Helge C, Dorfmueller, Alistair J P, Brown, Neil A R, Gow |
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| Rok vydání: | 2020 |
| Předmět: |
GPI
glycosylphosphatidylinositol WGA wheat germ agglutinin rpm revolutions per minute 3D three dimensions Chitin β-glucan Article PBS phosphate buffered saline PRRs pattern recognition receptors Cell wall proteins CWPs cell wall proteins ChBD chitin binding domain SEM scanning electron microscopy Fungal cell wall ultrastructure NMR nuclear magnetic resonance TEM transmission electron microscopy EndoH endoglycosidase H 2° secondary HPF/FS high pressure freezing/freeze substitution OD600 optical density at 600 nm carbohydrates (lipids) AFM atomic force microscopy 3° tertiary Fc-dectin-1 soluble chimeric form of dectin-1 HuCκ human kappa light chain N-mannan BSA bovine serum albumin 6xHis hexahistidine tag PAMPs pathogen associated molecular patterns scAb single chain antibody 2D two dimensions |
| Zdroj: | The Cell Surface |
| ISSN: | 2468-2330 |
| Popis: | Highlights • In wild type C. albicans yeast cells grown in standard lab conditions: • Chitin microfibrils are interspersed throughout the inner layer of the cell wall. • Cell wall proteins are embedded throughout the inner layer of the cell wall. • The outer fibrillar layer represents N-mannan outer chains. • The length of fibrils correlates with the length of the α(1,6)-N-mannan backbone. • Side chains extend from the α(1,6)-backbone at fixed angles every 10 mannose residues. Despite the importance of fungal cell walls as the principle determinant of fungal morphology and the defining element determining fungal interactions with other cells, few scalar models have been developed that reconcile chemical and microscopic attributes of its structure. The cell wall of the fungal pathogen Candida albicans is comprised of an amorphous inner skeletal layer of β(1,3)- and β(1,6)-glucan and chitin and an outer fibrillar layer thought to be dominated by highly mannosylated cell wall proteins. The architecture of these two layers can be resolved at the electron microscopy level, but the visualised structure of the wall has not yet been defined precisely in chemical terms. We have therefore examined the precise structure, location and molecular sizes of the cell wall components using transmission electron microscopy and tomography and tested predictions of the cell wall models using mutants and agents that perturb the normal cell wall structure. We demonstrate that the fibrils are comprised of a frond of N-linked outer chain mannans linked to a basal layer of GPI-proteins concentrated in the mid-wall region and that the non-elastic chitin microfibrils are cantilevered with sufficient lengths of non-fibrillar chitin and/or β-glucan to enable the chitin-glucan cage to flex, e.g. during morphogenesis and osmotic swelling. We present the first three-dimensional nano-scalar model of the C. albicans cell wall which can be used to test hypotheses relating to the structure–function relationships that underpin the pathobiology of this fungal pathogen. |
| Databáze: | OpenAIRE |
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