scholarly journals Hex1, the Major Component of Woronin Bodies, is Required for Normal Development, Pathogenicity and Stress Response in the Plant Pathogenic Fungus Verticillium dahliae

2020 ◽  
Author(s):  
Vasileios Vangalis ◽  
Ioannis A. Papaioannou ◽  
Emmanouil A. Markakis ◽  
Michael Knop ◽  
Milton A. Typas

AbstractWoronin bodies are membrane-bound organelles of filamentous ascomycetes that mediate hyphal compartmentalization by plugging septal pores upon hyphal damage. Their major component is the peroxisomal protein Hex1, which has also been implicated in additional cellular processes in fungi. Here, we analyzed the Hex1 homolog of Verticillium dahliae, an important asexual plant pathogen, and we report its pleiotropic involvement in fungal growth, physiology, stress response and pathogenicity. Alternative splicing of the Vdhex1 gene can lead to the production of two Hex1 isoforms, which are structurally similar to their Neurospora crassa homolog. We show that VdHex1 is targeted to the septum, consistently with its demonstrated function in sealing hyphal compartments to prevent excessive cytoplasmic bleeding upon injury. Furthermore, our investigation provides direct evidence for significant contributions of Hex1 in growth and morphogenesis, as well as in asexual reproduction capacity. We discovered that Hex1 is required both for normal responses to osmotic stress and factors that affect the cell wall and plasma membrane integrity, and for normal resistance to oxidative stress and ROS homeostasis. The Vdhex1 mutant exhibited diminished ability to colonize and cause disease on eggplant. Overall, we show that Hex1 has fundamentally important multifaceted roles in the biology of V. dahliae.

2020 ◽  
Vol 6 (4) ◽  
pp. 344
Author(s):  
Vasileios Vangalis ◽  
Ioannis A. Papaioannou ◽  
Emmanouil A. Markakis ◽  
Michael Knop ◽  
Milton A. Typas

Woronin bodies are membrane-bound organelles of filamentous ascomycetes that mediate hyphal compartmentalization by plugging septal pores upon hyphal damage. Their major component is the peroxisomal protein Hex1, which has also been implicated in additional cellular processes in fungi. Here, we analyzed the Hex1 homolog of Verticillium dahliae, an important asexual plant pathogen, and we report its pleiotropic involvement in fungal growth, physiology, stress response, and pathogenicity. Alternative splicing of the Vdhex1 gene can lead to the production of two Hex1 isoforms, which are structurally similar to their Neurospora crassa homolog. We show that VdHex1 is targeted to the septum, consistently with its demonstrated function in sealing hyphal compartments to prevent excessive cytoplasmic bleeding upon injury. Furthermore, our investigation provides direct evidence for significant contributions of Hex1 in growth and morphogenesis, as well as in asexual reproduction capacity. We discovered that Hex1 is required both for normal responses to osmotic stress and factors that affect the cell wall and plasma-membrane integrity, and for normal resistance to oxidative stress and reactive oxygen species (ROS) homeostasis. The Vdhex1 mutant exhibited diminished ability to colonize and cause disease on eggplant. Overall, we show that Hex1 has fundamentally important multifaceted roles in the biology of V. dahliae.


2019 ◽  
Vol 11 (22) ◽  
pp. 2905-2917 ◽  
Author(s):  
Rodrigo Rollin-Pinheiro ◽  
Victor Pereira Rochetti ◽  
Mariana Ingrid Dutra da Silva Xisto ◽  
Livia Cristina Liporagi-Lopes ◽  
Beatriz Bastos ◽  
...  

Aim: Glycosphingolipids are conserved lipids displaying a variety of functions in fungal cells, such as determination of cell polarity and virulence. They have been considered as potent targets for new antifungal drugs. The present work aimed to test two inhibitors, myriocin and DL-threo-1-Phenyl-2-palmitoylamino-3-morpholino-1-propanol, in Scedosporium boydii, a pathogenic fungus which causes a wide range of disease. Materials & methods: Mass spectrometry, microscopy and cell biology approaches showed that treatment with both inhibitors led to defects in fungal growth and membrane integrity, and caused an increased susceptibility to the current antifungal agents. Conclusion: These data demonstrate the antifungal potential of drugs inhibiting sphingolipid biosynthesis, as well as the usefulness of sphingolipids as promising targets for the development of new therapeutic options.


2014 ◽  
Vol 1 (1) ◽  
pp. 62-67 ◽  
Author(s):  
M. Mandygra ◽  
A. Lysytsia

Aim. To investigate the effect of polyhexamethyleneguanidine (PHMG) to eukaryotic cell culture. Methods. The passaged bovine tracheal cells culture (TCC) and primary culture of chicken embryo fi broblasts (FCE) were used in the experiments. TCC and FCE monolayers were treated with aqueous solutions of PHMG chloride or succinate. The method of PHMG polycation adsorption to the cells’ plasma membrane together with microscopy were applied. Results. The dependence of PHMG effect on the eukaryotic cells on the agent concentration, duration of exposure and the anion type has been fi xed. The PHMG concentration of 10 –5 per cent (0.1 μg/ml) never causes degradation of the previously formed cell monolayer, while the higher concentrations damage it. The conditions of the PHMG chloride and succinate’s negative effect on cell proliferation and inhibition of monolayer formation were determined. The hypothesis that under certain conditions PHMG stimulates the proliferative activity of the cells has been confi rmed. Stimulation may be associated with non-specifi c stress adaptation of cells. In this case, it is due to modifi cations of the cell membrane after PHMG adsorption to it. Conclusions. PHMG polycation binds with the membrane’s phosphoglycerides fi rmly and irreversibly. A portion of the lipids are removed from participation in the normal cellular processes at that. At the same time, the synthesis of new lipids and membrane-bound enzymes is probably accelerated. The phospholip ids’ neogenesis acceleration can stimulate mitosis under certain conditions. The obtained results can be used in the biotechnologies.


2021 ◽  
Vol 22 ◽  
Author(s):  
Sitansu Sekhar Nanda ◽  
Md Imran Hossain ◽  
Heongkyu Ju ◽  
Dong Kee Yi

Background: GSK-3 inhibitors became a novel therapeutic agent treating cancer. There are so many uses of GSK-3 inhibitor for treating cancer like breast cancer, lung cancer, gastric cancer, and no pathological changes are shown by the morphological examination of GSK-3. Objectives: This review describes the recent affairs using GSK-3 inhibitors, mainly treating in colon carcinoma. The authorsAuthors have also shown the different mechanisms of different GSK-3 inhibitors for treating various cancers and proposed some mechanisms that can be useful for further research by GSK-3 inhibitors for various cancerscancer including colon carcinoma. Results: The majority of the cancers and pre-cancerous lesions are stimulated by the transformation of membrane-bound arachidonic acid (AA) to eicosanoids for the viability, proliferation, and spread of cancer. GSK-3 inhibitors can reinstate hostility to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) responsiveness in gastric adenocarcinoma cells. GSK-3, the final enzyme in glycogen synthesis, is a serine/threonine kinase that phosphorylates varied sequences that are more than a hundred in number, within proteins in an array of heterogeneous pathways. It is an essential module of an exceptionally huge number of cellular processes, a fundamental role in many metabolic processes and diseases. Many patients achieve long term remission with outstanding survival diagnosed with colon cancer through it. Conclusion: Before the extensive application of these proposed mechanisms of GSK-3 inhibitor, further evaluation and clinical studies are needed. After doing the appropriate clinical studies and morphological examination, it can be appropriate for extensive application.


2000 ◽  
Vol 44 (6) ◽  
pp. 1418-1427 ◽  
Author(s):  
L. E. Alksne ◽  
P. Burgio ◽  
W. Hu ◽  
B. Feld ◽  
M. P. Singh ◽  
...  

ABSTRACT Protein secretion is an essential process for bacterial growth, yet there are few if any antimicrobial agents which inhibit secretion. An in vivo, high-throughput screen to detect secretion inhibitors was developed based on the translational autoregulation of one of the central protein components, SecA. The assay makes use of a SecA-LacZ fusion reporter construct in Escherichia coli which is induced when secretion is perturbed. Several compounds, including two natural product extracts, which had the ability to induce the reporter fusion were identified and the MICs of these compounds forStaphylococcus aureus strain MN8 were found to be ≤128 μg/ml. Enzyme-linked immunosorbent assay, Western blotting, and immunoprecipitation techniques were used to analyze the affects of these compounds on protein secretion. Six representative compounds presented here appear to be bona fide secretion inhibitors but were found to have deleterious effects on membranes. It was concluded that, while the method described here for identifying inhibitors of secretion is valid, screens such as this, which are directed against the membrane-bound portion of a pathway, may preferentially identify compounds which affect membrane integrity.


Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 357 ◽  
Author(s):  
Elwira Sieniawska ◽  
Rafał Sawicki ◽  
Joanna Golus ◽  
Milen I. Georgiev

The antimycobacterial activity of cinnamaldehyde has already been proven for laboratory strains and for clinical isolates. What is more, cinnamaldehyde was shown to threaten the mycobacterial plasma membrane integrity and to activate the stress response system. Following promising applications of metabolomics in drug discovery and development we aimed to explore the mycobacteria response to cinnamaldehyde within cinnamon essential oil treatment by untargeted liquid chromatography–mass spectrometry. The use of predictive metabolite pathway analysis and description of produced lipids enabled the evaluation of the stress symptoms shown by bacteria. This study suggests that bacteria exposed to cinnamaldehyde could reorganize their outer membrane as a physical barrier against stress factors. They probably lowered cell wall permeability and inner membrane fluidity, and possibly redirected carbon flow to store energy in triacylglycerols. Being a reactive compound, cinnamaldehyde may also contribute to disturbances in bacteria redox homeostasis and detoxification mechanisms.


Nova Hedwigia ◽  
2020 ◽  
Vol 110 (3) ◽  
pp. 247-267
Author(s):  
Trashi Singh ◽  
Pushpendra Kumar Dwivedi ◽  
Suvendra Nath Bagchi

An axenic culture of a cyanobacterium in the spent medium produced hexane-extracta- ble compound(s) that antagonized growth of several Gram+ve and –ve bacteria, including a few potential pathogens. Phylogenetic investigations classified the strain to be Anabaena fertilissima strain CCC597. Using Escherichia coli MTCC443 as a test organism, we have shown that ROS (O 2; H 2O 2) production and outer and inner membrane (OM: IM) permeabilization were induced upon such treatments. Consequently, leakage of proteins and cytosolic acidification processes were initi- ated. Suppression of cytoplasmic membrane-bound respiratory O 2consumption was most likely the physiological aberration that killed the bacteria. Several antioxidant enzymes viz. superoxide dis- mutase, catalase, and peroxidases showed concomitant increase in the enzymatic activities and band intensities in the corresponding substrate gels. Notwithstanding, the counteraction mechanism(s) was not preventive, and sufficient oxidative radicals still generated to manifest lipid peroxidation. Chemical analysis of the hexane-extract of A. fertilissima culture filtrates revealed presence of a number of long chain unsaturated fatty acids, including cis-13,16-docosadienoic acid, with proven antibacterial properties.


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