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

Abstract

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.

A combined chemical and enzymatic method to determine quantitatively the polysaccharide components in the cell wall of yeasts

“…To enlarge our study, we conducted a biochemical analysis of cell wall composition in response to various environmental stresses as well as to the treatment with caspofungin, an antifungal drug acting specifically on b-(1,3)-glucan synthase (Deresinski & Stevens, 2003). When yeast cells were transferred from 30 to 42°C, we recently showed using atomic force microscopy (AFM) technology, the formation of a circular structure at the cell surface that takes its origins at a single punctuated source and propagates into concentric manner to reach a diameter of 2-3 lm (Pillet et al, 2014). In addition, as reported in Table 4, the heat shock at 42°C caused a 45% reduction of the b-(1,3)-glucan that was accompanied by 20% rise in b-(1,6)-glucan (P < 0.01) and by a twofold increase of chitin (P < 0.001).…”

Mechanisms of L‐lysine extraction with sec‐octylphenoxy acetic acid in sulfonated kerosene

“…AFM is a powerful characterization tool to reveal the local surface molecular structure and chemical composition of materials with superior spatial resolution, which has already been successfully applied to study the morphologies and interaction mechanisms of ion channels, protein extraction, short peptides and heat shock protein . In this study, the high‐resolution AFM was utilized to clearly reveal the molecular structure of L‐Lys and CA‐12, as well as the interaction between L‐Lys and CA‐12 in the extraction phase.…”

Yeast cell disruption strategies for recovery of intracellular bio-active compounds — A review

“…Another two physical methods are the osmotic shock and thermolysis, where a cell suspension involves dilution after equilibration in high osmotic pressure and heat treatment, respectively. They have found a few applications in yeast cell disruptions (Crotti, Drgon, & Cabib, 2001;Bzducha-Wróbel et al, 2014;Wang et al, 2014;Pillet et al, 2014;Yusaf et al, 2015). Pillet et al (2014) explored the biophysical response of the yeast Saccharomyces cerevisiae to a temperature stress from 30°C to 42°C and found a dysfunction in the budding process caused by the heat shock.…”

“…They have found a few applications in yeast cell disruptions (Crotti, Drgon, & Cabib, 2001;Bzducha-Wróbel et al, 2014;Wang et al, 2014;Pillet et al, 2014;Yusaf et al, 2015). Pillet et al (2014) explored the biophysical response of the yeast Saccharomyces cerevisiae to a temperature stress from 30°C to 42°C and found a dysfunction in the budding process caused by the heat shock. Yusaf et al (2015) determined the required shock pressure to disrupt a single yeast cell and the rupture location on the cell wall by a numerical and experimental study.…”