scholarly journals Structural elucidation of novel phosphocholine-containing glycosylinositol-phosphoceramides in filamentous fungi and their induction of cell death of cultured rice cells

2004 ◽  
Vol 378 (2) ◽  
pp. 461-472 ◽  
Author(s):  
Kazuhiro AOKI ◽  
Ryosuke UCHIYAMA ◽  
Saki ITONORI ◽  
Mutsumi SUGITA ◽  
Fang-Sik CHE ◽  
...  
Keyword(s):  
Cell Death ◽  
Filamentous Fungi ◽  
Periodate Oxidation ◽  
Compositional Analysis ◽  
Major Fatty Acid ◽  
Mannose Residue ◽  
Ionization Time ◽  
Chemical Structures ◽  
Terminal Mannose ◽  
Fast Atom Bombardment Ms

Novel ZGLs (zwitterionic glycosphingolipids) have been found in and extracted from the mycelia of filamentous fungi (Acremonium sp.) isolated from soil. Five ZGLs (ZGL1–ZGL5) were structurally elucidated by sugar compositional analysis, methylation analysis, periodate oxidation, matrix-assisted laser-desorption ionization–time-of-flight MS, 1H-NMR spectroscopy and fast-atom bombardment MS. Their chemical structures were as follows: GlcN(α1-2)Ins1-P-1Cer (ZGL1), Man(α1-6)GlcN(α1-2)Ins1-P-1Cer (ZGL2), Man(α1-6)Man(α1-6)GlcN(α1-2)Ins1-P-1Cer (ZGL3), PC→6Man(α1-6)GlcN(α1-2)Ins1-P-1Cer (ZGL4), and PC→6Man(α1-6)Man(α1-6)GlcN(α1-2)Ins1-P-1Cer (ZGL5) (where Cer is ceramide and PC is phosphocholine). In addition, one acidic glycosphingolipid, which was the precursor of ZGLs, was also characterized as inositol-phosphoceramide. The core structure of the ZGLs, GlcN(α1-2)Ins1-P, is rather different from those found in other fungi, such as Man(α1-2)Ins1-P and Man(α1-6)Ins1-P. Interestingly, the terminal mannose residue of ZGL4 and ZGL5 was modified further with a PC group. The presence of PC-containing glycosylinositol-phosphoceramides has not been reported previously in any organism. The ceramide constituents of both ZGLs and acidic glycosphingolipid were essentially the same, and consisted of a 4-hydroxyoctadecasphinganine (phytosphingosine) as the sole sphingoid base and 2-hydroxytetracosanoic acid (>90%) as the major fatty acid. ZGLs were found to cause cell death in suspensions of cultured rice cells. The cell death-inducing activity of ZGLs is probably due to the characteristic glycan moiety of Man(α1-6)GlcN, and PC-containing ZGLs had high activity. This study is the first to demonstrate that fungal glycosylinositol-phosphoceramides induce cell death in cultured rice cells.

Biotransformation of Coumarins by Filamentous Fungi: An Alternative Way for Achievement of Bioactive Analogs

2019 ◽  
Vol 16 (6) ◽  
pp. 568-577 ◽  
Author(s):  
Jainara Santos do Nascimento ◽  
João Carlos Silva Conceição ◽  
Eliane de Oliveira Silva
Keyword(s):  
Filamentous Fungi ◽  
Chemical Reactions ◽  
Biological Activities ◽  
Chemical Transformations ◽  
Chemical Structures ◽  
Pattern Structures ◽  
Pharmacological Interest ◽  
Aspergillus Sp ◽  
The Impact ◽  
Related Compounds

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.

scholarly journals The transfer of mannose to dolichol diphosphate oligosaccharides in pig liver endoplasmic reticulum

1975 ◽  
Vol 152 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Gerard J. A. Oliver ◽  
Frank W. Hemming
Keyword(s):  
Endoplasmic Reticulum ◽  
Periodate Oxidation ◽  
The Other ◽  
Microsomal Preparation ◽  
Pig Liver ◽  
Mannose Residue ◽  
Chromatographic Data ◽  
Endogenous Lipid

The transfer, catalysed by pig liver microsomal preparations, of mannose, from GDP-mannose, to lipid-linked oligosaccharides and the properties of the products are described. Solubility, hydrolytic and chromatographic data suggest that they are dolichol diphosphate derivatives. The presence of two N-acetyl groups in at least part of the heterogenous oligosaccharide portion was tentatively deduced. Reduction with borohydride of the oligosaccharide showed that the newly added mannose residues were not at its reducing end. Periodate oxidation suggested that 60% of these were at the non-reducing terminus and that 40% were positioned internally. T.l.c. showed the presence of seven oligosaccharide fractions with chromatographic mobilities corresponding to glucose oligomers with 7–13 residues. The molar proportions of the oligosaccharide fractions in the mixture were determined by borotritiide reduction and the number of mannose residues added to each oligosaccharide fraction during the incubation was calculated. Two of the oligosaccharide fractions had received on average one, or slightly more than one, mannose residue per chain during the incubation; four of the other fractions were each shown to be a mixture, 20–25% of which had received one mannose residue during the incubation and 75–80% of which had not been mannosylated during the incubation. This supported other evidence for the presence of endogenous lipid-linked oligosaccharides in the microsomal preparation which had been formed before the incubation in vitro. Evidence for the possibility of two pools of dolichol monophosphate mannose, one being more closely associated with mannosyl transfer to dolichol diphosphate oligosaccharides than the other, is also discussed.

scholarly journals VIB-1 Is Required for Expression of Genes Necessary for Programmed Cell Death in Neurospora crassa

2006 ◽  
Vol 5 (12) ◽  
pp. 2161-2173 ◽  
Author(s):  
Karine Dementhon ◽  
Gopal Iyer ◽  
N. Louise Glass
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Neurospora Crassa ◽  
Filamentous Fungi ◽  
Somatic Growth ◽  
Genetic Differences ◽  
Extracellular Proteases ◽  
Hyphal Fusion ◽  
Expression Of Genes ◽  
Nonself Recognition

ABSTRACT Nonself recognition during somatic growth is an essential and ubiquitous phenomenon in both prokaryotic and eukaryotic species. In filamentous fungi, nonself recognition is also important during vegetative growth. Hyphal fusion between genetically dissimilar individuals results in rejection of heterokaryon formation and in programmed cell death of the fusion compartment. In filamentous fungi, such as Neurospora crassa, nonself recognition and heterokaryon incompatibility (HI) are regulated by genetic differences at het loci. In N. crassa, mutations at the vib-1 locus suppress nonself recognition and HI mediated by genetic differences at het-c/pin-c, mat, and un-24/het-6. vib-1 is a homolog of Saccharomyces cerevisiae NDT80, which is a transcriptional activator of genes during meiosis. For this study, we determined that vib-1 encodes a nuclear protein and showed that VIB-1 localization varies during asexual reproduction and during HI. vib-1 is required for the expression of genes involved in nonself recognition and HI, including pin-c, tol, and het-6; all of these genes encode proteins containing a HET domain. vib-1 is also required for the production of downstream effectors associated with HI, including the production of extracellular proteases upon carbon and nitrogen starvation. Our data support a model in which mechanisms associated with starvation and nonself recognition/HI are interconnected. VIB-1 is a major regulator of responses to nitrogen and carbon starvation and is essential for the expression of genes involved in nonself recognition and death in N. crassa.

scholarly journals Partial Prion Cross-Seeding between Fungal and Mammalian Amyloid Signaling Motifs

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thierry Bardin ◽  
Asen Daskalov ◽  
Sophie Barrouilhet ◽  
Alexandra Granger-Farbos ◽  
Bénédicte Salin ◽  
...  
Keyword(s):  
Cell Death ◽  
Filamentous Fungi ◽  
Sequence Similarity ◽  
Podospora Anserina ◽  
Content Type ◽  
Cell Death Pathways ◽  
Prion Propagation ◽  
Signaling Modules ◽  
Β Sheet

ABSTRACT In filamentous fungi, NLR-based signalosomes activate downstream membrane-targeting cell death-inducing proteins by a mechanism of amyloid templating. In the species Podospora anserina, two such signalosomes, NWD2/HET-S and FNT1/HELLF, have been described. An analogous system involving a distinct amyloid signaling motif, termed PP, was also identified in the genome of the species Chaetomium globosum and studied using heterologous expression in Podospora anserina. The PP motif bears resemblance to the RIP homotypic interaction motif (RHIM) and to RHIM-like motifs controlling necroptosis in mammals and innate immunity in flies. We identify here a third NLR signalosome in Podospora anserina comprising a PP motif and organized as a two-gene cluster encoding an NLR and an HELL domain cell death execution protein termed HELLP. We show that the PP motif region of HELLP forms a prion we term [π] and that [π] prions trigger the cell death-inducing activity of full-length HELLP. We detect no prion cross-seeding between HET-S, HELLF, and HELLP amyloid motifs. In addition, we find that, like PP motifs, RHIMs from human RIP1 and RIP3 kinases are able to form prions in Podospora and that [π] and [Rhim] prions partially cross-seed. Our study shows that Podospora anserina displays three independent cell death-inducing amyloid signalosomes. Based on the described functional similarity between RHIM and PP, it appears likely that these amyloid motifs constitute evolutionarily related cell death signaling modules. IMPORTANCE Amyloids are β-sheet-rich protein polymers that can be pathological or display a variety of biological roles. In filamentous fungi, specific immune receptors activate programmed cell death execution proteins through a process of amyloid templating akin to prion propagation. Among these fungal amyloid signaling sequences, the PP motif stands out because it shows similarity to the RHIM, an amyloid sequence controlling necroptotic cell death in mammals. We characterized an amyloid signaling system comprising a PP motif in the model species Podospora anserina, thus bringing to three the number of independent amyloid signaling cell death pathways described in that species. We then showed that human RHIMs not only propagate as prions in P. anserina but also partially cross-seed with fungal PP prions. These results indicate that, in addition to showing sequence similarity, the PP and RHIM motifs are at least partially functionally related, supporting a model of long-term evolutionary conservation of amyloid signaling mechanisms from fungi to mammals.

scholarly journals Characterization of the Antigenic Lipopolysaccharide O Chain and the Capsular Polysaccharide Produced by Actinobacillus pleuropneumoniae Serotype 13

2004 ◽  
Vol 72 (10) ◽  
pp. 5925-5930 ◽  
Author(s):  
Leann L. MacLean ◽  
Malcolm B. Perry ◽  
Evguenii Vinogradov
Keyword(s):  
Capsular Polysaccharide ◽  
Teichoic Acid ◽  
Periodate Oxidation ◽  
Actinobacillus Pleuropneumoniae ◽  
Antigenic Specificity ◽  
Resonance Spectroscopy ◽  
Type I ◽  
Specific Chemical ◽  
Chemical Structures ◽  
Acid Type

ABSTRACT Serotyping of Actinobacillus pleuropneumoniae, the etiologic agent of porcine pleuropneumonia, is important for epidemiological studies and for the development of homologous vaccine cell preparations. The serology is based on the specific chemical structures of capsular polysaccharides (CPSs) and lipopolysaccharide (LPS) antigenic O-polysaccharide moieties (O-PSs), and knowledge of these structures is required for a molecular-level understanding of their serological specificities. The structures of A. pleuropneumoniae serotype 1 to 12 CPSs and O-PSs have been elucidated; however, the structures associated with three newly proposed serotypes (serotypes 13, 14, and 15) have not been reported. Herein we described the structures of the antigenic O-PS and CPS of A. pleuropneumoniae serotype 13. The O-PS of the A. pleuropneumoniae serotype 13 LPS is a polymer of branched tetrasaccharide repeating units composed of l-rhamnose, 2-acetamido-2-deoxy-d-galactose, and d-galactose residues (1:1:2). By use of hydrolysis, methylation, and periodate oxidation chemical methods together with the application of one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy and mass spectrometry, the structures of the O chain and CPS were determined. The CPS of A. pleuropneumoniae serotype 13 was characterized as a teichoic-acid type polymer. The LPS O antigen was identical to the O-PS produced by A. pleuropneumoniae serotype 7. The CPS has the unique structure of a 1,3-poly(glycerol phosphate) teichoic acid type I polymer and constitutes the macromolecule defining the A. pleuropneumoniae serotype 13 antigenic specificity.

Beech wood treated with polyglycerol succinate: a new effective method for its protection and stabilization

Holzforschung ◽  
2020 ◽  
Vol 74 (4) ◽  
pp. 351-361 ◽  
Author(s):  
Clément L’Hostis ◽  
Emmanuel Fredon ◽  
Marie-France Thévenon ◽  
Francisco-José Santiago-Medina ◽  
Philippe Gérardin
Keyword(s):  
Beech Wood ◽  
Treated Wood ◽  
Weight Percent ◽  
Decay Resistance ◽  
Curing Temperature ◽  
Ionization Time ◽  
Chemical Structures ◽  
Treatment Conditions ◽  
Middle Infrared

AbstractThis paper deals with an original and non-biocidal chemical treatment consisting of a vacuum/pressure impregnation step of beech wood with a water-borne mixture made from heat-activated condensation of succinic anhydride (SA) and glycerol (G). Chemical structures of adducts were established using matrix-assisted laser desorption ionization time-of-flight mass spectroscopy (MALDI-TOF) investigations. Beech wood was impregnated and cured in order to induce in situ polymerization of glycerol/succinic adducts (GSA) in the cell walls, leading to the formation of polyglycerol succinate (PGS) polyester. Various treatment conditions were investigated depending on the duration (6–72 h) and curing temperature (103–160°C). Weight percent gains (WPGs) ranging between 40 and 60% were obtained. Attenuated total reflectance-middle infrared spectroscopy (ATR-MIR) and carbon-13 nuclear magnetic resonance (13C-NMR) spectroscopy confirmed polyester formation. A curing temperature of 160°C was found to be the best condition to totally avoid polymer leaching, and brought the anti-swelling efficiency (ASE) up to 64%. Decay resistance of PGS-treated wood against Trametes versicolor and Coniophora puteana was also strongly temperature and time dependent: performances fit with the EN113 standard requirements if a curing temperature of 160°C was applied.

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