scholarly journals Mechanisms of Contact-Mediated Killing of Yeast Cells on Dry Metallic Copper Surfaces

2010 ◽  
Vol 77 (2) ◽  
pp. 416-426 ◽  
Author(s):  
Davide Quaranta ◽  
Travis Krans ◽  
Christophe Espírito Santo ◽  
Christian G. Elowsky ◽  
Dylan W. Domaille ◽  
...  
Keyword(s):  
Copper Ions ◽  
Metallic Copper ◽  
Membrane Damage ◽  
Ion Homeostasis ◽  
Genetic Material ◽  
Copper Ion ◽  
Yeast Cells ◽  
Wild Type ◽  
Copper Surfaces ◽  
Mutant Cells

ABSTRACTSurfaces made of copper or its alloys have strong antimicrobial properties against a wide variety of microorganisms. However, the molecular mode of action responsible for the antimicrobial efficacy of metallic copper is not known. Here, we show that dry copper surfaces inactivateCandida albicansandSaccharomyces cerevisiaewithin minutes in a process called contact-mediated killing. Cellular copper ion homeostasis systems influenced the kinetics of contact-mediated killing in both organisms. Deregulated copper ion uptake through a hyperactiveS. cerevisiaeCtr1p (ScCtr1p) copper uptake transporter inSaccharomycesresulted in faster inactivation of mutant cells than of wild-type cells. Similarly, lack of theC. albicansCrp1p (CaCrp1p) copper-efflux P-type ATPase or the metallothionein CaCup1p caused more-rapid killing ofCandidamutant cells than of wild-type cells.CandidaandSaccharomycestook up large quantities of copper ions as soon as they were in contact with copper surfaces, as indicated by inductively coupled plasma mass spectroscopy (ICP-MS) analysis and by the intracellular copper ion-reporting dye coppersensor-1. Exposure to metallic copper did not cause lethality through genotoxicity, deleterious action on a cell's genetic material, as indicated by a mutation assay withSaccharomyces. Instead, toxicity mediated by metallic copper surfaces targeted membranes in both yeast species. With the use of Live/Dead staining, onset of rapid and extensive cytoplasmic membrane damage was observed in cells from copper surfaces. Fluorescence microscopy using the indicator dye DiSBaC2(3) indicated that cell membranes were depolarized. Also, during contact-mediated killing, vacuoles first became enlarged and then disappeared from the cells. Lastly, in metallic copper-stressed yeasts, oxidative stress in the cytoplasm and in mitochondria was elevated.

scholarly journals Bacterial Killing by Dry Metallic Copper Surfaces

2010 ◽  
Vol 77 (3) ◽  
pp. 794-802 ◽  
Author(s):  
Christophe Espírito Santo ◽  
Ee Wen Lam ◽  
Christian G. Elowsky ◽  
Davide Quaranta ◽  
Dylan W. Domaille ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Scientific Explanation ◽  
Copper Ions ◽  
Metallic Copper ◽  
Membrane Damage ◽  
Dna Lesions ◽  
Cell Integrity ◽  
Copper Uptake ◽  
Bacterial Killing ◽  
Copper Surfaces

ABSTRACTMetallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important first steps for revealing the molecular sensitive targets in cells lethally challenged by exposure to copper surfaces and provide a scientific explanation for the use of copper surfaces as antimicrobial agents for supporting public hygiene.

scholarly journals Isolation and Characterization of Bacteria Resistant to Metallic Copper Surfaces

2010 ◽  
Vol 76 (5) ◽  
pp. 1341-1348 ◽  
Author(s):  
Christophe Esp�rito Santo ◽  
Paula Vasconcelos Morais ◽  
Gregor Grass
Keyword(s):  
Copper Ions ◽  
Copper Alloys ◽  
Metallic Copper ◽  
Copper Ion ◽  
Copper Surface ◽  
Bacterial Strains ◽  
Copper Surfaces ◽  
Isolation And Characterization ◽  
Detoxification Systems

ABSTRACT Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coins comprise strains that are especially resistant against the toxic properties exerted by dry metallic copper surfaces. The most resistant of 294 isolates were Gram-positive staphylococci and micrococci, Kocuria palustris, and Brachybacterium conglomeratum but also included the proteobacterial species Sphingomonas panni and Pseudomonas oleovorans. Cells of some of these bacterial strains survived on copper surfaces for 48 h or more. Remarkably, when these dry-surface-resistant strains were exposed to moist copper surfaces, resistance levels were close to those of control strains and MICs for copper ions were at or below control strain levels. This suggests that mechanisms conferring resistance against dry metallic copper surfaces in these newly isolated bacterial strains are different from well-characterized copper ion detoxification systems. Furthermore, staphylococci on coins did not exhibit increased levels of resistance to antibiotics, arguing against coselection with copper surface resistance traits.

scholarly journals Contribution of Copper Ion Resistance to Survival of Escherichia coli on Metallic Copper Surfaces

2007 ◽  
Vol 74 (4) ◽  
pp. 977-986 ◽  
Author(s):  
Christophe Espírito Santo ◽  
Nadine Taudte ◽  
Dietrich H. Nies ◽  
Gregor Grass
Keyword(s):  
Escherichia Coli ◽  
Metallic Copper ◽  
Survival Rates ◽  
Copper Ion ◽  
Copper Surface ◽  
Bacterial Inactivation ◽  
Wild Type ◽  
Copper Surfaces ◽  
Detoxification Systems ◽  
Copper Chelators

ABSTRACT Bacterial contamination of touch surfaces poses a serious threat for public health. The use of bactericidal surface materials, such as copper and its alloys, might constitute a way to aid the use of antibiotics and disinfectants, thus minimizing the risk of emergence and spread of multiresistant germs. The survival of Escherichia coli on metallic copper surfaces has been studied previously; however, the mechanisms underlying bacterial inactivation on copper surfaces have not been elucidated. Data presented in this study suggest that bacteria are killed rapidly on dry copper surfaces. Several factors, such as copper ion toxicity, copper chelators, cold, osmotic stress, and reactive oxygen species, but not anaerobiosis, influenced killing rates. Strains deleted in copper detoxification systems were slightly more sensitive than was the wild type. Preadaptation to copper enhanced survival rates upon copper surface exposure. This study constitutes a first step toward understanding the reasons for metallic copper surface-mediated killing of bacteria.

scholarly journals Screening for Modulators of Spermine Tolerance Identifies Sky1, the SR Protein Kinase of Saccharomyces cerevisiae, as a Regulator of Polyamine Transport and Ion Homeostasis

2001 ◽  
Vol 21 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Omri Erez ◽  
Chaim Kahana
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Osmotic Shock ◽  
Ion Homeostasis ◽  
Inorganic Ions ◽  
Yeast Cells ◽  
Wild Type ◽  
Sr Protein ◽  
Polyamine Transport ◽  
Increased Sensitivity

ABSTRACT Although most cells are capable of transporting polyamines, the mechanism that regulates polyamine transport in eukaryotes is still largely unknown. Using a genetic screen for clones capable of restoring spermine sensitivity to spermine-tolerant mutants ofSaccharomyces cerevisiae, we have demonstrated that Sky1p, a recently identified SR protein kinase, is a key regulator of polyamine transport. Yeast cells deleted for SKY1 developed tolerance to toxic levels of spermine, while overexpression of Sky1p in wild-type cells increased their sensitivity to spermine. Expression of the wild-type Sky1p but not of a catalytically inactive mutant restored sensitivity to spermine. SKY1 disruption results in dramatically reduced uptake of spermine, spermidine, and putrescine. In addition to spermine tolerance, sky1Δ cells exhibit increased tolerance to lithium and sodium ions but somewhat increased sensitivity to osmotic shock. The observed halotolerance suggests potential regulatory interaction between the transport of polyamines and inorganic ions, as suggested in the case of the Ptk2p, a recently described regulator of polyamine transport. We demonstrate that these two kinases act in two different signaling pathways. While deletion or overexpression of SKY1 did not significantly affect Pma1p activity, the ability of overexpressed Sky1p, Ptk1p, and Ptk2p to increase sensitivity to LiCl depends on the integrity ofPPZ1 but not of ENA1.

scholarly journals Antimicrobial metallic copper surfaces kill Staphylococcus haemolyticus via membrane damage

2012 ◽  
Vol 1 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Christophe Espírito Santo ◽  
Davide Quaranta ◽  
Gregor Grass
Keyword(s):  
Metallic Copper ◽  
Membrane Damage ◽  
Copper Surfaces ◽  
Staphylococcus Haemolyticus

scholarly journals The number of cytokinesis nodes in mitotic fission yeast scales with cell volume

2021 ◽  
Author(s):  
Wasim A Sayyad ◽  
Thomas D Pollard
Keyword(s):  
Plasma Membrane ◽  
Fission Yeast ◽  
Large Population ◽  
Yeast Cells ◽  
Wild Type ◽  
Contractile Ring ◽  
Node Number ◽  
Nmt1 Promoter ◽  
Wide Range ◽  
Mutant Cells

Cytokinesis nodes are assemblies of stoichiometric ratios of proteins associated with the plasma membrane, which serve as precursors for the contractile ring during cytokinesis by fission yeast. The total number of nodes is uncertain, because of the limitations of the methods used previously. Here we used the ~140 nm resolution of Airyscan confocal microscopy to resolve a large population of dim, unitary cytokinesis nodes in 3D reconstructions of whole fission yeast cells. Wild-type fission yeast cells make about 200 unitary cytokinesis nodes. Most, but not all of these nodes condense into a contractile ring. The number of cytokinesis nodes scales with cell size in four strains tested, although wide rga4Δ mutant cells form somewhat fewer cytokinesis nodes than expected from the overall trend. The surface density of Pom1 kinase on the plasma membrane around the equators of cells is similar with a wide range of node numbers, so Pom1 does not control cytokinesis node number. However, varying protein concentrations with the nmt1 promoter showed that the numbers of nodes increase above a baseline of about 200 with the total cellular concentration of either Pom1 or the kinase Cdr2.

The requirement for yeast superoxide dismutase is bypassed through mutations in BSD2, a novel metal homeostasis gene

1994 ◽  
Vol 14 (11) ◽  
pp. 7037-7045
Author(s):  
X F Liu ◽  
V C Culotta
Keyword(s):  
Superoxide Dismutase ◽  
Gene Deletion ◽  
Copper Ions ◽  
Cadmium Toxicity ◽  
Copper Ion ◽  
Oxygen Toxicity ◽  
Yeast Cells ◽  
Yeast Strains ◽  
Increased Sensitivity ◽  
Probable Role

Oxygen toxicity in Saccharomyces cerevisiae strains lacking superoxide dismutase can be suppressed through mutations in either the BSD1 or BSD2 gene. In this report, we demonstrate that the BSD2 gene normally functions in the homeostasis of heavy metal ions. A mutation in BSD2 not only reverses the aerobic defects of yeast strains lacking superoxide dismutase but also is associated with an increased sensitivity to copper and cadmium toxicity and an elevation in copper ion accumulation. The BSD2 gene was cloned by functional complementation and is predicted to encode a novel 37.5-kDa protein with three potential transmembrane domains. The mutant bsd2-1 allele was isolated and found to contain a single C-to-T transition changing a centrally located proline to a serine. This substitution results in total inactivation of BSD2, since the bsd2-1 mutation is identical to a bsd2 delta gene deletion in phenotype. BSD2 is expressed in yeast cells as a 1.5-kb mRNA. Although the gene functions in copper detoxification, BSD2 is not induced by copper ions, as is the case with S. cerevisiae metallothioneins. A probable role for copper ions in the bsd2 reversal of oxidative damage is discussed.

scholarly journals Mapping the Polarity of Changes That Occur in Interrupted CAG Repeat Tracts in Yeast

1998 ◽  
Vol 18 (8) ◽  
pp. 4597-4604 ◽  
Author(s):  
Debra J. Maurer ◽  
Brennon L. O’Callaghan ◽  
Dennis M. Livingston
Keyword(s):  
Mismatch Repair ◽  
Trinucleotide Repeat ◽  
Cag Repeat ◽  
Yeast Cells ◽  
Wild Type ◽  
Repeat Tract ◽  
Repeat Units ◽  
Length Changes ◽  
Mutant Cells ◽  
Lagging Strand

ABSTRACT To explore the mechanisms by which CAG trinucleotide repeat tracts undergo length changes in yeast cells, we examined the polarity of alterations with respect to an interrupting CAT trinucleotide near the center of the tract. In wild-type cells, in which most tract changes are large contractions, the changes that retain the interruption are biased toward the 3′ end of the repeat tract (in reference to the direction of lagging-strand synthesis). In rth1/rad27mutant cells that are defective in Okazaki fragment maturation, the tract expansions are biased to the 5′ end of the repeat tract, while the tract contractions that do not remove the interruption occur randomly on either side of the interruption. In msh2 mutant cells that are defective in the mismatch repair machinery, neither the small changes of one or two repeat units nor the larger contractions attributable to this mutation are biased to either side of the interruption. The results of this study are discussed in terms of the molecular paths leading to expansions and contractions of repeat tracts.

scholarly journals Investigations of Accessibility of T2/T3 Copper Center of Two-Domain Laccase from Streptomyces griseoflavus Ac-993

2019 ◽  
Vol 20 (13) ◽  
pp. 3184 ◽  
Author(s):  
Azat Gabdulkhakov ◽  
Ilya Kolyadenko ◽  
Olga Kostareva ◽  
Alisa Mikhaylina ◽  
Paulo Oliveira ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Copper Ions ◽  
Copper Ion ◽  
Imidazole Ring ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Wild Type ◽  
Related Substances ◽  
Copper Center ◽  
Mutant Forms

Laccases (EC 1.10.3.2) are multicopper oxidoreductases acting on diphenols and related substances. Laccases are highly important for biotechnology and environmental remediation. These enzymes contain mononuclear one T2 copper ion and two T3 copper ions (Cu3α and Cu3β), which form the so-called trinuclear center (TNC). Along with the typical three-domain laccases Bacteria produce two-domain (2D) enzymes, which are active at neutral and basic pH, thermostable, and resistant to inhibitors. In this work we present the comparative analysis of crystal structures and catalytic properties of recombinant 2D laccase from Streptomyces griseoflavus Ac-993 (SgfSL) and its four mutant forms with replacements of two amino acid residues, located at the narrowing of the presumable T3-solvent tunnels. We obtained inactive enzymes with substitutions of His165, with Phe, and Ile170 with Ala or Phe. His165Ala variant was more active than the wild type. We suggest that His165 is a “gateway” at the O2-tunnel leading from solvent to the Cu3β of the enzyme. The side chain of Ile170 could be indirectly involved in the coordination of copper ions at the T3 center by maintaining the position of the imidazole ring of His157 that belongs to the first coordination sphere of Cu3α.

scholarly journals Insufficiency of Copper Ion Homeostasis Causes Freeze-Thaw Injury of Yeast Cells as Revealed by Indirect Gene Expression Analysis

2009 ◽  
Vol 75 (21) ◽  
pp. 6706-6711 ◽  
Author(s):  
Shunsuke Takahashi ◽  
Akira Ando ◽  
Hiroshi Takagi ◽  
Jun Shima
Keyword(s):  
Gene Expression ◽  
Cell Viability ◽  
Expression Analysis ◽  
Gene Expression Analysis ◽  
Copper Ions ◽  
Ion Homeostasis ◽  
Copper Ion ◽  
Freeze Thaw ◽  
Metal Ion Homeostasis ◽  
Freezing Period

ABSTRACT Saccharomyces cerevisiae is exposed to freeze-thaw stress in commercial processes, including frozen dough baking. Cell viability and fermentation activity after a freeze-thaw cycle were dramatically decreased due to freeze-thaw injury. Because this type of injury involves complex phenomena, the injury mechanisms are not fully understood. We examined freeze-thaw injury by indirect gene expression analysis during postthaw incubation after freeze-thaw treatment using DNA microarray profiling. The results showed that genes involved in the homeostasis of metal ions were frequently contained in genes that were upregulated, depending on the freezing period. We assessed the phenotype of deletion mutants of the metal ion homeostasis genes that exhibited freezing period-dependent upregulation and found that the strains with deletion of the MAC1 and CTR1 genes involved in copper ion homeostasis exhibited freeze-thaw sensitivity, suggesting that copper ion homeostasis is required for freeze-thaw tolerance. We found that supplementation with copper ions during postthaw incubation increased intracellular superoxide dismutase activity and intracellular levels of reactive oxygen species were decreased. Moreover, cell viability was increased by supplementation with copper ions. These results suggest that insufficiency of copper ion homeostasis may be one of the causes of freeze-thaw injury.

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