Towards a nanoscale view of fungal surfaces

Dague, Étienne; Gilbert, Yann; Verbelen, Claire; André, Guillaume; Alsteens, David; Dufrêne, Yves F.

doi:10.1002/yea.1445

Cited by 26 publications

(17 citation statements)

References 28 publications

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“…Also, the cell surface morphology of mnn9Δ mutant defective in the initiation of mannan synthesis (Jungmann and Munro 1998) and of chs3Δ mutant defective in the main chitin synthase enzyme was relatively comparable between the exponential and stationary phases, and showed an apparently different topography to that of the wild‐type. These ultrastructural modifications were exquisitely confirmed by surface roughness measurements, which were obtained by recording force sensing between the tip and the surface (Dague et al , 2007b). The surface roughness was measured as a function of the increasing scanned area, and Table 1 summarizes the quantitative data collected for an integrated surface area of 5.6 × 10 5 nm 2 .…”

Section: Resultsmentioning

confidence: 93%

An atomic force microscopy analysis of yeast mutants defective in cell wall architecture

Dague

Bitar

Ranchon

et al. 2010

Yeast

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Yeast cells are surrounded by a thick cell wall, the composition and structure of which have been characterized by biochemical and genetic methods. In this study, we used atomic force microscopy (AFM) to visualize the cell surface topography and to determine cell wall nanomechanical properties of yeast mutants defective in cell wall architecture. While all mutants investigated showed some alteration in cell surface topography, this alteration was particularly salient in mutants defective in β-glucan elongation (gas1), chitin synthesis (chs3) and cross-linkages between chitin and β-glucan (crh1crh2). In addition, these alterations in surface topology were accompanied by increased roughness of the cell. From force-indentation curves, the Young's modulus was determined, as it gives a measure of the elasticity of the cell wall. A value of ∼1.6 MPa was obtained for the cell walls of the wild-type strain in exponential and stationary phases of growth. The same value was measured in a mnn9 mutant defective in protein mannosylation, and was two-fold reduced in a mutant with reduced β-glucan (fks1 and knr4 ), only in the stationary phase of growth. In contrast, the elasticity was dramatically reduced in mutants defective in chitin synthesis (chs3 ), β-glucan elongation (gas1 ) and, even more remarkably, in a crh1 crh2 mutant defective in the enzymes that catalyse cross-linkages of chitin to β-glucan. Taken together, these results provide direct physical evidence that the nanomechanical properties of the yeast cell wall are mainly dependent on cross-links and cell wall remodelling, rather than on cell wall composition or thickness.

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Section: Resultsmentioning

confidence: 93%

An atomic force microscopy analysis of yeast mutants defective in cell wall architecture

Dague

Bitar

Ranchon

et al. 2010

Yeast

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“…In fact, owing to its multiple capacities, AFM has the potential of becoming an important tool in cell interaction research (Dague et al 2007;Parot et al 2007). When combined with other microscopic imaging as confocal microscopy and with biochemical methods, these AFM-based experiments will contribute to shed new light on the structural and functional alteration relationships in glyphosate-treated keratinocytes.…”

Section: Introductionmentioning

confidence: 99%

Morphological damages of a glyphosate-treated human keratinocyte cell line revealed by a micro- to nanoscale microscopic investigation

et al. 2009

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Among the molecules to which the human skin is exposed, glyphosate is used as an herbicide. Glyphosate has been shown to induce in vitro cutaneous cytotoxic effects, concomitant with oxidative disorders. In this following study, we focused on dynamic events of the loss of HaCaT cell integrity appearing after a glyphosate treatment. In these conditions, we showed that glyphosate is able to disrupt HaCaT cells and to induce intracellular oxidative cascade. In this aim, we optimized the conditions of cell treatment playing on exposure time (from 24 h to 30 min), which directly modify the cell viability profile (glyphosate 50% inhibition concentration from 28 to 53 mM) and allow to track cells along the treatment as an "induction and visualization" process. The combination of atomic force and fluorescence microscopic approaches offered opportunities to lead in parallel an investigation of the membrane surface and of the intracellular disorders, through cytoskeleton, nuclear, and oxidative stress marker targeting. The originality of our approach relies on monitoring all events derived from oxidative stress in process and performed by simultaneous cytotoxic induction and nanoscale cell visualization. We revealed a transition from spread and globular to elongated cell morphology, with a drastic cell size reduction, after a dose- and time-dependent glyphosate treatment; a redistribution of cell surface protrusions was also pointed out. All these membrane damages, added to observations of disorganized cytoskeleton, condensed chromatin, and overproduction of oxidative reactive species, lead us to conclude that glyphosate acts in induction of apoptotic process.

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“…However, a direct visualization of the topography and nanomechanical changes associated to these biochemical and molecular changes induced by stresses was still missing to better understand the cell wall biogenesis and remodeling mechanism. The remarkable development of the Atomic Force Microscopy (AFM) technology, combined with genetical and molecular tools, is therefore powerful to fulfil this gap and investigate the dynamics of microbial cell surfaces in response to external cues [21,22]. …”

Section: Introductionmentioning

confidence: 99%

Uncovering by Atomic Force Microscopy of an original circular structure at the yeast cell surface in response to heat shock

et al. 2014

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BackgroundAtomic Force Microscopy (AFM) is a polyvalent tool that allows biological and mechanical studies of full living microorganisms, and therefore the comprehension of molecular mechanisms at the nanoscale level. By combining AFM with genetical and biochemical methods, we explored the biophysical response of the yeast Saccharomyces cerevisiae to a temperature stress from 30°C to 42°C during 1 h.ResultsWe report for the first time the formation of an unprecedented circular structure at the cell surface that takes its origin at a single punctuate source and propagates in a concentric manner to reach a diameter of 2–3 μm at least, thus significantly greater than a bud scar. Concomitantly, the cell wall stiffness determined by the Young’s Modulus of heat stressed cells increased two fold with a concurrent increase of chitin. This heat-induced circular structure was not found either in wsc1Δ or bck1Δ mutants that are defective in the CWI signaling pathway, nor in chs1Δ, chs3Δ and bni1Δ mutant cells, reported to be deficient in the proper budding process. It was also abolished in the presence of latrunculin A, a toxin known to destabilize actin cytoskeleton.ConclusionsOur results suggest that this singular morphological event occurring at the cell surface is due to a dysfunction in the budding machinery caused by the heat shock and that this phenomenon is under the control of the CWI pathway.

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Towards a nanoscale view of fungal surfaces

Cited by 26 publications

References 28 publications

An atomic force microscopy analysis of yeast mutants defective in cell wall architecture

An atomic force microscopy analysis of yeast mutants defective in cell wall architecture

Morphological damages of a glyphosate-treated human keratinocyte cell line revealed by a micro- to nanoscale microscopic investigation

Uncovering by Atomic Force Microscopy of an original circular structure at the yeast cell surface in response to heat shock

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