scholarly journals Species-specific differences in the susceptibility of fungi towards the antifungal protein AFP depend on C3 saturation of glycosylceramides

2019 ◽  
Author(s):  
Norman Paege ◽  
Dirk Warnecke ◽  
Simone Zäuner ◽  
Silke Hagen ◽  
Ana Rodrigues ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Fatty Acid ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Membrane Integrity ◽  
Structural Difference ◽  
Inhibitory Effects ◽  
Chitin Synthesis ◽  
Fatty Acid Chain ◽  
Damage Response

AbstractAFP is an antimicrobial peptide (AMP) produced by the filamentous fungus Aspergillus giganteus and a very potent inhibitor of fungal growth without affecting the viability of bacteria, plant or mammalian cells. It targets chitin synthesis and causes plasma membrane permeabilization in many human and plant pathogenic fungi, but its exact mode of action is not known. We have recently proposed adoption of the “damage-response framework of microbial pathogenesis” put forward by Pirofksi and Casadevall in 1999 regarding the analysis of interactions between AMPs and microorganisms, thus, predicting that the cytotoxic capacity of a given AMP is relative and depends not only on the presence/absence of its target(s) in the host and the AMP concentration applied but also on other variables, such as microbial survival strategies. We show here using the examples of three filamentous fungi (Aspergillus niger, Aspergillus fumigatus, Fusarium graminearum) and two yeasts (Saccharomyces cerevisiae, Pichia pastoris) that the important parameters defining the AFP susceptibilities of these fungi are (i) the presence/absence of glycosylceramides, (ii) the presence/absence of Δ3(E)-desaturation of the fatty acid chain therein, and (iii) the (dis)ability of these fungi to respond to AFP inhibitory effects with the fortification of their cell walls via increased chitin and β-(1,3)-glucan synthesis. These observations support the adoption of the damage-response framework to holistically understand the outcome of AFP inhibitory effects.ImportanceOur data suggest a fundamental role of glycosylceramides in the susceptibility of fungi towards AFP. We discovered that only a minor structural difference in these molecules – the saturation level of their fatty acid chain, controlled by a 2-hydroxy fatty N-acyl-Δ3(E)-desaturase – is a key to understanding the inhibitory activity of AFP. As glycosylceramides are important components of fungal plasma membranes, we propose a model which links AFP-mediated inhibition of chitin synthesis in fungi with its potential to disturb plasma membrane integrity.

scholarly journals Species-Specific Differences in the Susceptibility of Fungi to the Antifungal Protein AFP Depend on C-3 Saturation of Glycosylceramides

mSphere ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Norman Paege ◽  
Dirk Warnecke ◽  
Simone Zäuner ◽  
Silke Hagen ◽  
Ana Rodrigues ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Fatty Acid ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Membrane Integrity ◽  
Inhibitory Effects ◽  
Chitin Synthesis ◽  
Content Type ◽  
Fatty Acid Chain ◽  
Damage Response

ABSTRACT AFP is an antimicrobial peptide (AMP) produced by the filamentous fungus Aspergillus giganteus and is a very potent inhibitor of fungal growth that does not affect the viability of bacteria, plant, or mammalian cells. It targets chitin synthesis and causes plasma membrane permeabilization in many human- and plant-pathogenic fungi, but its exact mode of action is not known. After adoption of the “damage-response framework of microbial pathogenesis” regarding the analysis of interactions between AMPs and microorganisms, we have recently proposed that the cytotoxic capacity of a given AMP depends not only on the presence/absence of its target(s) in the host and the AMP concentration applied but also on other variables, such as microbial survival strategies. We show here using the examples of three filamentous fungi (Aspergillus niger, Aspergillus fumigatus, and Fusarium graminearum) and two yeasts (Saccharomyces cerevisiae and Pichia pastoris) that the important parameters defining the AFP susceptibilities of these fungi are (i) the presence/absence of glycosylceramides, (ii) the presence/absence of Δ3(E) desaturation of the fatty acid chain therein, and (iii) the (dis)ability of these fungi to respond to AFP inhibitory effects with the fortification of their cell walls via increased chitin and β-(1,3)-glucan synthesis. These observations support the idea of the adoption of the damage-response framework to holistically understand the outcome of AFP inhibitory effects. IMPORTANCE Our data suggest a fundamental role of glycosylceramides in the susceptibility of fungi to AFP. We discovered that only a minor structural difference in these molecules—namely, the saturation level of their fatty acid chain, controlled by a 2-hydroxy fatty N-acyl-Δ3(E)-desaturase—represents a key to understanding the inhibitory activity of AFP. As glycosylceramides are important components of fungal plasma membranes, we propose a model which links AFP-mediated inhibition of chitin synthesis in fungi with its potential to disturb plasma membrane integrity.

Characterization of two Mg2+transporters in sealed plasma membrane vesicles from rat liver

1998 ◽  
Vol 275 (4) ◽  
pp. C995-C1008 ◽  
Author(s):  
Christie Cefaratti ◽  
Andrea Romani ◽  
Antonio Scarpa
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Intracellular Signaling ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Membrane Vesicles ◽  
Channel Blockers ◽  
Transport Mechanisms ◽  
Plasma Membrane Vesicles ◽  
New Information

The plasma membrane of mammalian cells possesses rapid Mg2+ transport mechanisms. The identity of Mg2+ transporters is unknown, and so are their properties. In this study, Mg2+ transporters were characterized using a biochemically and morphologically standardized preparation of sealed rat liver plasma membranes (LPM) whose intravesicular content could be set and controlled. The system has the advantages that it is not regulated by intracellular signaling machinery and that the intravesicular ion milieu can be designed. The results indicate that 1) LPM retain trapped intravesicular total Mg2+with negligible leak; 2) the addition of Na+ or Ca2+ induces a concentration- and temperature-dependent efflux corresponding to 30–50% of the intravesicular Mg2+; 3) the rate of flux is very rapid (137.6 and 86.8 nmol total Mg2+ ⋅ μm−2 ⋅ min−1after Na+ and Ca2+ addition, respectively); 4) coaddition of maximal concentrations of Na+ and Ca2+ induces an additive Mg2+ efflux; 5) both Na+- and Ca2+-stimulated Mg2+ effluxes are inhibited by amiloride, imipramine, or quinidine but not by vanadate or Ca2+ channel blockers; 6) extracellular Na+ or Ca2+ can stimulate Mg2+ efflux in the absence of Mg2+ gradients; and 7) Mg2+ uptake occurs in LPM loaded with Na+ but not with Ca2+, thus indicating that Na+/Mg2+but not Ca2+/Mg2+exchange is reversible. These data are consistent with the operation of two distinct Mg2+ transport mechanisms and provide new information on rates of Mg2+ transport, specificity of the cotransported ions, and reversibility of the transport.

scholarly journals Sphingolipid Domains in the Plasma Membranes of Fibroblasts Are Not Enriched with Cholesterol

2013 ◽  
Vol 288 (23) ◽  
pp. 16855-16861 ◽  
Author(s):  
Jessica F. Frisz ◽  
Haley A. Klitzing ◽  
Kaiyan Lou ◽  
Ian D. Hutcheon ◽  
Peter K. Weber ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Plasma Membrane ◽  
High Resolution ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Secondary Ion Mass Spectrometry ◽  
Cholesterol Depletion ◽  
Fibroblast Cells ◽  
Secondary Ion ◽  
Rule Out

The plasma membranes of mammalian cells are widely expected to contain domains that are enriched with cholesterol and sphingolipids. In this work, we have used high-resolution secondary ion mass spectrometry to directly map the distributions of isotope-labeled cholesterol and sphingolipids in the plasma membranes of intact fibroblast cells. Although acute cholesterol depletion reduced sphingolipid domain abundance, cholesterol was evenly distributed throughout the plasma membrane and was not enriched within the sphingolipid domains. Thus, we rule out favorable cholesterol-sphingolipid interactions as dictating plasma membrane organization in fibroblast cells. Because the sphingolipid domains are disrupted by drugs that depolymerize the cells actin cytoskeleton, cholesterol must instead affect the sphingolipid organization via an indirect mechanism that involves the cytoskeleton.

scholarly journals The Relationship between Acrosome Reaction and Polyunsaturated Fatty Acid Composition in Boar Sperm

2019 ◽  
Author(s):  
Sang-Hee Lee ◽  
Yu-Jin Kim ◽  
Byeong Ho Kang ◽  
Choon-Keun Park
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Acid Composition ◽  
Acrosome Reaction ◽  
Membrane Integrity ◽  
Plasma Membrane Integrity ◽  
Boar Sperm ◽  
The Relationship

This study investigated the relationship of acrosome reactions and fatty acid composition on fertility in boar sperm. The acrosome reaction of sperm was induced via methyl-beta-cyclodextrin (MBCD), and acrosome reaction, plasma membrane integrity, and fertility were analyzed. The fatty acid composition of the excess acrosome reacted sperm was determined via gas chromatography. The results showed that the acrosome reaction in sperm was induced over 85% of the time by 60 mM MBCD treatment, and the plasma membrane integrity was significantly decreased and was dependent on the MBCD level. The acrosome reacted sperm resulted in significantly higher saturated fatty acids (SFAs) and lower unsaturated fatty acids (PUFAs) than the non-acrosome reaction group. Moreover, the acrosome reacted sperm from 60 mM MBCD significantly decreased in vitro fertility and blastocyst formation relative to non-acrosome reacted sperm, and the acrosome reaction was positively correlated with SFAs and negatively correlated with PUFAs. Of these fatty acids, C22:5n-6 (docosapentaenoic acid [DPA]) and C22:6n-3 (docosahexaenoic acid [DHA]) were directly negatively correlated with the acrosome reaction (r = -0.982 and -0.947, respectively). In conclusion, the excessive acrosome reactions may occur by reducing the PUFAs, which may then dramatically decrease sperm fertility in pigs.

scholarly journals Reprogramming cholesterol metabolism in macrophages and its role in host defense against cholesterol-dependent cytolysins

2022 ◽  
Author(s):  
Min-Sub Lee ◽  
Steven J. Bensinger
Keyword(s):  
Plasma Membrane ◽  
Host Defense ◽  
Mammalian Cells ◽  
Cholesterol Metabolism ◽  
Current Knowledge ◽  
Membrane Integrity ◽  
Cholesterol Homeostasis ◽  
Metabolic Reprogramming ◽  
Membrane Cholesterol ◽  
Plasma Membrane Cholesterol

AbstractCholesterol is a critical lipid for all mammalian cells, ensuring proper membrane integrity, fluidity, and biochemical function. Accumulating evidence indicates that macrophages rapidly and profoundly reprogram their cholesterol metabolism in response to activation signals to support host defense processes. However, our understanding of the molecular details underlying how and why cholesterol homeostasis is specifically reshaped during immune responses remains less well understood. This review discusses our current knowledge of cellular cholesterol homeostatic machinery and introduces emerging concepts regarding how plasma membrane cholesterol is partitioned into distinct pools. We then discuss how proinflammatory signals can markedly reshape the cholesterol metabolism of macrophages, with a focus on the differences between MyD88-dependent pattern recognition receptors and the interferon signaling pathway. We also discuss recent work investigating the capacity of these proinflammatory signals to selectively reshape plasma membrane cholesterol homeostasis. We examine how these changes in plasma membrane cholesterol metabolism influence sensitivity to a set of microbial pore-forming toxins known as cholesterol-dependent cytolysins that specifically target cholesterol for their effector functions. We also discuss whether lipid metabolic reprogramming can be leveraged for therapy to mitigate tissue damage mediated by cholesterol-dependent cytolysins in necrotizing fasciitis and other related infections. We expect that advancing our understanding of the crosstalk between metabolism and innate immunity will help explain how inflammation underlies metabolic diseases and highlight pathways that could be targeted to normalize metabolic homeostasis in disease states.

Vacuolar-type H(+)-ATPases are functionally expressed in plasma membranes of human tumor cells

1993 ◽  
Vol 265 (4) ◽  
pp. C1015-C1029 ◽  
Author(s):  
R. Martinez-Zaguilan ◽  
R. M. Lynch ◽  
G. M. Martinez ◽  
R. J. Gillies
Keyword(s):  
Plasma Membrane ◽  
Tumor Cells ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Human Tumor ◽  
Atp Depletion ◽  
Second Phase ◽  
Bafilomycin A1 ◽  
P Type

Mammalian cells generally regulate their intracellular pH (pHi) via collaboration between Na(+)-H+ exchanger and HCO3- transport. In addition, a number of normal mammalian cells have been identified that express H(+)-adenosinetriphosphatases (ATPases) in their plasma membranes. Because tumor cells often maintain a high pHi, we hypothesized that they might functionally express H(+)-ATPases in their plasma membranes. In the first phase of the present study, we screened 19 normal and tumorigenic human cell lines for the presence of plasmalemmal H(+)-ATPase activity using bafilomycin A1 to inhibit V-type H(+)-ATPase and Sch-28080 to inhibit P-type H(+)-K(+)-ATPase. Bafilomycin A1 decreased pHi in the six tumor cell lines with the highest resting pHi in the absence of HCO3-. Sch-28080 did not affect pHi in any of the human cells. Simultaneous measurement of pH in the cytoplasm and in the endosomes/lysosomes localized the activity of bafilomycin to the plasma membrane in three cell lines. In the second phase of this study, these three cell lines were shown to recover from NH4(+)-induced acid loads in the absence of Na+. This recovery was inhibited by N-ethylmaleimide, bafilomycin A1, and ATP depletion and was not significantly affected by vanadate, Sch-28080, or hexamethyl amiloride. These results indicate that a vacuolar type H(+)-ATPase is expressed in the plasma membrane of some tumor cells.

scholarly journals The Ca2+-activated polyphosphoinositide phosphodiesterase of human and rabbit neutrophil membranes

1984 ◽  
Vol 221 (2) ◽  
pp. 477-482 ◽  
Author(s):  
S Cockcroft ◽  
J M Baldwin ◽  
D Allan
Keyword(s):  
Fatty Acid Composition ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Phospholipase C ◽  
Acid Composition ◽  
Membrane Fraction ◽  
Plasma Membranes ◽  
Degradation Products ◽  
Diacylglycerol Kinase ◽  
Plasma Membrane Fraction

Addition of Ca2+ to a plasma-membrane fraction derived from human or rabbit neutrophils led to the specific breakdown of polyphosphoinositides. The degradation products were identified as diacylglycerol and inositol bis- and tris-phosphate, thus demonstrating the presence of a Ca2+-activated phospholipase C. The newly generated diacylglycerol resembled the polyphosphoinositides in its fatty acid composition, and in the presence of MgATP2- it was converted into phosphatidate. These results therefore demonstrate the presence in neutrophil plasma membranes not only of polyphosphoinositide phosphodiesterase but also of diacylglycerol kinase.

scholarly journals Physiological and Transcriptional Responses of Saccharomyces cerevisiae tod-Limonene Show Changes to the Cell Wall but Not to the Plasma Membrane

2013 ◽  
Vol 79 (12) ◽  
pp. 3590-3600 ◽  
Author(s):  
Timothy C. R. Brennan ◽  
Jens O. Krömer ◽  
Lars K. Nielsen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Structural Integrity ◽  
Fatty Acid Biosynthesis ◽  
Membrane Integrity ◽  
Ethanol Exposure ◽  
Yeast Cells ◽  
Transcriptional Responses

ABSTRACTMonoterpenes can, upon hydrogenation, be used as light-fraction components of sustainable aviation fuels. Fermentative production of monoterpenes in engineered microorganisms, such asSaccharomyces cerevisiae, has gained attention as a potential route to deliver these next-generation fuels from renewable biomass. However, end product toxicity presents a formidable problem for microbial synthesis. Due to their hydrophobicity, monoterpene inhibition has long been attributed to membrane interference, but the molecular mechanism remains largely unsolved. In order to gain a better understanding of the mode of action, we analyzed the composition and structural integrity of the cell envelope as well as the transcriptional response of yeast cells treated with an inhibitory amount ofd-limonene (107 mg/liter). We found no alterations in membrane fluidity, structural membrane integrity, or fatty acid composition after the solvent challenge. A 4-fold increase in the mean fluorescence intensity per cell (using calcofluor white stain) and increased sensitivity to cell wall-degrading enzymes demonstrated that limonene disrupts cell wall properties. Global transcript measurements confirmed the membrane integrity observations by showing no upregulation of ergosterol or fatty acid biosynthesis pathways, which are commonly overexpressed in yeast to reinforce membrane rigidity during ethanol exposure. Limonene shock did cause a compensatory response to cell wall damage through overexpression of several genes (ROM1,RLM1,PIR3,CTT1,YGP1,MLP1,PST1, andCWP1) involved with the cell wall integrity signaling pathway. This is the first report demonstrating that cell wall, rather than plasma membrane, deterioration is the main source of monoterpene inhibition. We show that limonene can alter the structure and function of the cell wall, which has a clear effect on cytokinesis.

scholarly journals Higly fusogenic cationic liposomes transiently permeabilize the plasma membrane of HeLa cells

2007 ◽  
Vol 12 (1) ◽  
Author(s):  
Katarzyna Stebelska ◽  
Paulina Wyrozumska ◽  
Jerzy Gubernator ◽  
Aleksander Sikorski
Keyword(s):  
Plasma Membrane ◽  
Nucleic Acids ◽  
Propidium Iodide ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Morphological Changes ◽  
Membrane Integrity ◽  
Cationic Liposomes ◽  
Endosomal Membrane

AbstractCationic liposomes can efficiently carry nucleic acids into mammalian cells. This property is tightly connected with their ability to fuse with negatively charged natural membranes (i.e. the plasma membrane and endosomal membrane). We used FRET to monitor and compare the efficiency of lipid mixing of two liposomal preparations — one of short-chained diC14-amidine and one of long-chained unsaturated DOTAP — with the plasma membrane of HeLa cells. The diC14-amidine liposomes displayed a much higher susceptibility to lipid mixing with the target membranes. They disrupted the membrane integrity of the HeLa cells, as detected using the propidium iodide permeabilization test. Morphological changes were transient and essentially did not affect the viability of the HeLa cells. The diC14-amidine liposomes were much more effective at either inducing lipid mixing or facilitating transfection.

Effect of protein corona on nanoparticle–plasma membrane and nanoparticle–biomimetic membrane interactions

2020 ◽  
Vol 7 (3) ◽  
pp. 963-974
Author(s):  
Lu Wang ◽  
Nicolas Hartel ◽  
Kaixuan Ren ◽  
Nicholas Alexander Graham ◽  
Noah Malmstadt
Keyword(s):  
Plasma Membrane ◽  
Systematic Study ◽  
Electrostatic Interactions ◽  
Plasma Membranes ◽  
Membrane Integrity ◽  
Protein Corona ◽  
Membrane Interactions ◽  
Biomimetic Membranes ◽  
Biomimetic Membrane

A systematic study of the protein corona's effect on nanoparticle–biomembrane electrostatic interactions. Nanoparticle adhesion and membrane integrity upon interaction were compared between plasma membranes and biomimetic membranes.

Sign in / Sign up

Export Citation Format

Share Document