scholarly journals Phosphatidic acid produced by phospholipase D is required for hyphal cell-cell fusion and fungal-plant symbiosis

2019 ◽  
Author(s):  
Berit Hassing ◽  
Carla J. Eaton ◽  
David Winter ◽  
Kimberly A. Green ◽  
Ulrike Brandt ◽  
...  

SummaryAlthough lipid signaling has been shown to serve crucial roles in mammals and plants, little is known about this process in filamentous fungi. Here we analyse the contribution of phospholipase D (PLD) and its product phosphatidic acid (PA) in hyphal morphogenesis and growth of Epichloë festucae and Neurospora crassa, and in the establishment of a symbiotic interaction between E. festucae and Lolium perenne. Growth of E. festucae and N. crassa PLD deletion strains in axenic culture, and for E. festucae in association with L. perenne, were analysed by light-, confocal- and electron microscopy. Changes in PA distribution were analysed in E. festucae using a PA biosensor and the impact of these changes on endocytic recycling and superoxide production investigated. We found that E. festucae PldB and the N. crassa ortholog, PLA-7, are required for polarized growth, cell fusion and ascospore development, whereas PldA/PLA-8 are dispensable for these functions. Exogenous addition of PA rescues the cell-fusion phenotype in E. festucae. PldB is also crucial for E. festucae to establish a symbiotic association with L. perenne. This study identifies a new component of the cell-cell communication and cell fusion signaling network that controls hyphal morphogenesis and growth in filamentous fungi.

2020 ◽  
Vol 113 (6) ◽  
pp. 1101-1121 ◽  
Author(s):  
Berit Hassing ◽  
Carla J. Eaton ◽  
David Winter ◽  
Kimberly A. Green ◽  
Ulrike Brandt ◽  
...  

2016 ◽  
Vol 90 (23) ◽  
pp. 10535-10544 ◽  
Author(s):  
Doina Atanasiu ◽  
Wan Ting Saw ◽  
Roselyn J. Eisenberg ◽  
Gary H. Cohen

ABSTRACTReceptor-dependent herpes simplex virus (HSV)-induced cell-cell fusion requires glycoproteins gD, gH/gL, and gB. Our current model posits that during fusion, receptor-activated conformational changes in gD activate gH/gL, which subsequently triggers the transformation of the prefusion form of gB into a fusogenic state. To examine the role of each glycoprotein in receptor-dependent cell-cell fusion, we took advantage of our discovery that fusion by wild-type herpes simplex virus 2 (HSV-2) glycoproteins occurs twice as fast as that achieved by HSV-1 glycoproteins. By sequentially swapping each glycoprotein between the two serotypes, we established that fusion speed was governed by gH/gL, with gH being the main contributor. While the mutant forms of gB fuse at distinct rates that are dictated by their molecular structure, these restrictions can be overcome by gH/gL of HSV-2 (gH2/gL2), thereby enhancing their activity. We also found that deregulated forms of gD of HSV-1 (gD1) and gH2/gL2can alter the fusogenic potential of gB, promoting cell fusion in the absence of a cellular receptor, and that deregulated forms of gB can drive the fusion machinery to even higher levels. Low pH enhanced fusion by affecting the structure of both gB and gH/gL mutants. Together, our data highlight the complexity of the fusion machinery, the impact of the activation state of each glycoprotein on the fusion process, and the critical role of gH/gL in regulating HSV-induced fusion.IMPORTANCECell-cell fusion mediated by HSV glycoproteins requires gD, gH/gL, gB, and a gD receptor. Here, we show that fusion by wild-type HSV-2 glycoproteins occurs twice as fast as that achieved by HSV-1 glycoproteins. By sequentially swapping each glycoprotein between the two serotypes, we found that the fusion process was controlled by gH/gL. Restrictions imposed on the gB structure by mutations could be overcome by gH2/gL2, enhancing the activity of the mutants. Under low-pH conditions or when using deregulated forms of gD1and gH2/gL2, the fusogenic potential of gB could only be increased in the absence of receptor, underlining the exquisite regulation that occurs in the presence of receptor. Our data highlight the complexity of the fusion machinery, the impact of the activation state of each glycoprotein on the fusion process, and the critical role of gH/gL in regulating HSV-induced fusion.


2019 ◽  
Vol 16 (6) ◽  
pp. 568-577 ◽  
Author(s):  
Jainara Santos do Nascimento ◽  
João Carlos Silva Conceição ◽  
Eliane de Oliveira Silva

Coumarins are natural 1,2-benzopyrones, present in remarkable amounts as secondary metabolites in edible and medicinal plants. The low yield in the coumarins isolation from natural sources, along with the difficulties faced by the total synthesis, make them attractive for biotechnological studies. The current literature contains several reports on the biotransformation of coumarins by fungi, which can generate chemical analogs with high selectivity, using mild and eco-friendly conditions. Prompted by the enormous pharmacological interest in the coumarin-related compounds, their alimentary and chemical applications, this review covers the biotransformation of coumarins by filamentous fungi. The chemical structures of the analogs were presented and compared with those from the pattern structures. The main chemical reactions catalyzed the insertion of functional groups, and the impact on the biological activities caused by the chemical transformations were discussed. Several chemical reactions can be catalyzed by filamentous fungi in the coumarin scores, mainly lactone ring opening, C3-C4 reduction and hydroxylation. Chunninghamella sp. and Aspergillus sp. are the most common fungi used in these transformations. Concerning the substrates, the biotransformation of pyranocoumarins is a rarer process. Sometimes, the bioactivities were improved by the chemical modifications and coincidences with the mammalian metabolism were pointed out.


PLoS ONE ◽  
2009 ◽  
Vol 4 (7) ◽  
pp. e6130 ◽  
Author(s):  
Yoshiyuki Yamada ◽  
Xiao Bo Liu ◽  
Shou Guo Fang ◽  
Felicia P. L. Tay ◽  
Ding Xiang Liu

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1144
Author(s):  
Aliyu Dantani Abdullahi ◽  
Pratthana Kodchasee ◽  
Kridsada Unban ◽  
Thanawat Pattananandecha ◽  
Chalermpong Saenjum ◽  
...  

The study investigated the impact of the fermentation process on the phenolic contents and antioxidant and anti-inflammatory activities in extracts of Miang, an ethnic fermented tea product of northern Thailand. The acetone (80%) extraction of Miang samples fermented by a non-filamentous fungi-based process (NFP) and filamentous fungi-based process (FFP) had elevated levels of total polyphenols, total tannins, and condensed tannins compared to young and mature tea leaves. The antioxidant studies also showed better the half-maximal inhibitory concentration (IC50) values for fermented leaves in both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity assays as well as improved ferric reducing antioxidant power (FRAP) compared to young and mature tea leaves. Extracts of NFP and FFP samples at concentrations of 50 and 100 ppm showed better protective effects against hydrogen peroxide (H2O2)-induced intracellular reactive oxygen species (ROS) production in HT-29 colorectal cells without exerting cytotoxicity. Additionally, lipopolysaccharide (LPS)-induced production of nitric oxide (a proinflammatory mediator as well as a reactive nitrogen species) was also inhibited by these fermented Miang extracts with an IC50 values of 17.15 μg/mL (NFP), 20.17 μg/mL (FFP), 33.96 μg/mL (young tea leaves), and 31.33 μg/mL (mature tea leaves). Therefore, both NFP-Miang and FFP-Miang showed the potential to be targeted as natural bioactive functional ingredients with preventive properties against free radical and inflammatory-mediated diseases.


1989 ◽  
Vol 16 (3) ◽  
pp. 257-262
Author(s):  
Lena Gustavsson ◽  
Christofer Lundqvist ◽  
Christer Ailing

The effects of phorbol esters on phospholipase D activity were studied in C-6 glioma cells. The cell lipids were prelabelled with [3H]-glycerol or [14C]-arachidonic acid. Phosphatidylethanol was formed during stimulation with 100nM 12-0-tetradecanoylphorbol-13-acetate (TPA), when ethanol was present in the culture medium. After 30 minutes of stimulation, phosphatidylethanol constituted 2.6% of the [3H]-glycerol-labelled lipids. Stimulating the cells with TPA in the absence of ethanol caused a significant increase in labelled phosphatidic acid. This increase was inhibited by ethanol. The present findings demonstrate that TPA stimulates phospholipase D activity in cultured C-6 glioma cells.


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