scholarly journals Unveiling the function and regulation control of the DUF3129 family proteins in fungal infection of hosts

2019 ◽  
Vol 374 (1767) ◽  
pp. 20180321 ◽  
Author(s):  
Wei Huang ◽  
Song Hong ◽  
Guirong Tang ◽  
Yuzhen Lu ◽  
Chengshu Wang
Keyword(s):  
Lipid Droplets ◽  
Fungal Pathogens ◽  
Pathogenic Fungus ◽  
Fungal Species ◽  
Wild Type ◽  
Metarhizium Robertsii ◽  
Host Interactions ◽  
Eukaryotic Proteins ◽  
Insect Pathogens ◽  
Mutant Cells

Many prokaryotic and eukaryotic proteins contain domains of unknown function (DUFs). A DUF3129 family of proteins is widely encoded in the genomes of fungal pathogens. A few studies in plant and insect pathogens indicated that the DUF3129 genes are required for fungal penetration of host cuticles with an unclear mechanism. We found that a varied number of DUF3129 proteins is present in different fungal species and the proteins are evolutionarily diverged from each other at the inter- and intra-specific levels. By using the insect pathogenic fungus Metarhizium robertsii as a model, we performed experiments and found that the seven DUF3129 proteins encoded by this fungus are localized to cellular lipid droplets (LDs). Individual deletion of these genes did not affect fungal formation of the infection structure appressoria and the accumulation of LDs in fungal conidia. When compared with the wild-type (WT) strain, insect bioassays revealed that the virulence of most null mutants were significantly impaired during topical infection but not during injection of insects. Carbon starvation and the subsequent Western blot analysis indicated that the LD-specific perilipin protein was completely degraded in the WT cells whereas varied levels of perilipin could be detected in the mutant cells, which signified that depletion of LD content was delayed in mutant cells, and DUF3129 proteins are therefore involved in LD degradation. We also provided biochemical evidence that these DUF3129 genes are transcriptionally regulated by a yeast Ste12-like transcription factor. The findings of this study not only unveil the function of DUF3129 proteins but also better understand the diverse mechanism of fungus–host interactions. This article is part of the theme issue ‘Biotic signalling sheds light on smart pest management’.

scholarly journals Enhanced Resistance To Fungal Pathogens in Transgenic Peanut (Arachis Hypogaea L.) Cultivar L14 by Overexpression of Gene encoding Chitinase 42 kDa from Trichoderma Asperellum SH16

2021 ◽  
Author(s):  
Phung Thi Bich Hoa ◽  
Nguyen Hoang Tue ◽  
Huynh Thi Quynh Trang ◽  
Hoang Anh Thu ◽  
Le Ngoc Huyen Nhung ◽  
...  
Keyword(s):  
Arachis Hypogaea ◽  
Fungal Pathogens ◽  
Pathogenic Fungus ◽  
Chitinase Activity ◽  
Trichoderma Asperellum ◽  
Wild Type ◽  
Synthetic Genes ◽  
Chitinase Genes ◽  
Transgenic Peanut

Abstract This study reports the expression of 42 kDa chitinase genes from Trichoderma asperellum SH16 in peanut (Arachis hypogaea) roots under the regulation of tissue-specific Asy promoter through Agrobacterium tumefaciens-mediated transformation. The 42 kDa chitinase genes, including one wild-type sequence (Chi42) and two synthetic sequences (syncodChi42-1 and syncodChi42-2) which were optimized for codon usage for plant expression, were incorporated into the peanut genome and successfully expressed in their roots. The investigation revealed that the enzyme chitinase from two synthetic genes had higher activity than that from the wild-type gene, about 901 U/mg (140 U/mL) and 1124 U/mg (197 U/mL) vs about 508 U/mg (87 U/mL). Transgenic peanut roots also exhibited extracellular chitinase activity which was driven by signal peptide of rice amylase 3D gene against the pathogenic fungus Sclerotium rolfsii under in vitro conditions. The higher chitinase activity of two synthetic genes in peanut roots promises potential applications in the field of transgenic crops against phytopathogenic fungi.

scholarly journals MrSkn7 Controls Sporulation, Cell Wall Integrity, Autolysis, and Virulence in Metarhizium robertsii

2015 ◽  
Vol 14 (4) ◽  
pp. 396-405 ◽  
Author(s):  
Yanfang Shang ◽  
Peilin Chen ◽  
Yixiong Chen ◽  
Yuzhen Lu ◽  
Chengshu Wang
Keyword(s):  
Cell Wall ◽  
Target Genes ◽  
Response Regulator ◽  
Pathogenic Fungus ◽  
Functional Divergence ◽  
Pathogenic Fungi ◽  
Wild Type ◽  
Metarhizium Robertsii ◽  
Content Type ◽  
Cell Autolysis

ABSTRACT Two-component signaling pathways generally include sensor histidine kinases and response regulators. We identified an ortholog of the response regulator protein Skn7 in the insect-pathogenic fungus Metarhizium robertsii , which we named MrSkn7. Gene deletion assays and functional characterizations indicated that MrSkn7 functions as a transcription factor. The MrSkn7 null mutant of M. robertsii lost the ability to sporulate and had defects in cell wall biosynthesis but was not sensitive to oxidative and osmotic stresses compared to the wild type. However, the mutant was able to produce spores under salt stress. Insect bioassays using these spores showed that the virulence of the mutant was significantly impaired compared to that of the wild type due to the failures to form the infection structure appressorium and evade host immunity. In particular, deletion of MrSkn7 triggered cell autolysis with typical features such as cell vacuolization, downregulation of repressor genes, and upregulation of autolysis-related genes such as extracellular chitinases and proteases. Promoter binding assays confirmed that MrSkn7 could directly or indirectly control different putative target genes. Taken together, the results of this study help us understand the functional divergence of Skn7 orthologs as well as the mechanisms underlying the development and control of virulence in insect-pathogenic fungi.

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

Control of Winged Waterprimrose (Jussiaea decurrens) and Northern Jointvetch (Aeschynomene virginica) with Fungal Pathogens

Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 497-501 ◽  
Author(s):  
C. D. Boyette ◽  
G. E. Templeton ◽  
R. J. Smith
Keyword(s):  
Oryza Sativa ◽  
Glycine Max ◽  
Fungal Pathogens ◽  
Liquid Culture ◽  
Field Experiments ◽  
Colletotrichum Gloeosporioides ◽  
Pathogenic Fungus ◽  
Field Tests ◽  
Wide Range ◽  
Growing Region

An indigenous, host-specific, pathogenic fungus that parasitizes winged waterprimrose [Jussiaea decurrens(Walt.) DC.] is endemic in the rice growing region of Arkansas. The fungus was isolated and identified asColletotrichum gloeosporioides(Penz.) Sacc. f.sp. jussiaeae(CGJ). It is highly specific for parasitism of winged waterprimrose and not parasitic on creeping waterprimrose (J. repensL. var.glabrescensKtze.), rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 4 other crops and 13 other weeds. The fungus was physiologically distinct from C.gloeosporioides(Penz.) Sacc. f. sp.aeschynomene(CGA), an endemic anthracnose pathogen of northern jointvetch[Aeschynomene virginica(L.) B.S.P.], as indicated by cross inoculations of both weeds. Culture in the laboratory and inoculation of winged waterprimrose in greenhouse, growth chamber and field experiments indicated that the pathogen was stable, specific, and virulent in a wide range of environments. The pathogen yielded large quantities of spores in liquid culture. It is suitable for control of winged waterprimrose. Winged waterprimrose and northern jointvetch were controlled in greenhouse and field tests by application of spore mixtures of CGJ and CGA at concentrations of 1 to 2 million spores/ml of each fungus in 94 L/ha of water; the fungi did not damage rice or nontarget crops.

scholarly journals Post-translational regulation of autophagy is involved in intra-microbiome suppression of fungal pathogens

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jing Wang ◽  
Chaoyun Xu ◽  
Qiming Sun ◽  
Jinrong Xu ◽  
Yunrong Chai ◽  
...  
Keyword(s):  
Translational Regulation ◽  
Fungal Pathogens ◽  
Fungal Growth ◽  
Fungal Species ◽  
26S Proteasome ◽  
Healthy Plant ◽  
Autophagy Induction ◽  
Histone Acetyltransferase Gcn5 ◽  
Plant Microbiota ◽  
Autophagic Process

Abstract Background Microbiome interactions are important determinants for ecosystem functioning, stability, and health. In previous studies, it was often observed that bacteria suppress potentially pathogenic fungal species that are part of the same plant microbiota; however, the underlying microbe-microbe interplay remains mostly elusive. Here, we explored antagonistic interactions of the fungus Fusarium graminearum and bacterium Streptomyces hygroscopicus at the molecular level. Both are ubiquitous members of the healthy wheat microbiota; under dysbiosis, the fungus causes devastating diseases. Results In co-cultures, we found that Streptomyces alters the fungal acetylome leading to substantial induction of fungal autophagy. The bacterium secrets rapamycin to inactivate the target of rapamycin (TOR), which subsequently promotes the degradation of the fungal histone acetyltransferase Gcn5 through the 26S proteasome. Gcn5 negatively regulates fungal autophagy by acetylating the autophagy-related protein Atg8 at the lysine site K13 and blocking cellular relocalization of Atg8. Thus, degradation of Gcn5 triggered by rapamycin was found to reduce Atg8 acetylation, resulting in autophagy induction in F. graminearum. Conclusions Autophagy homeostasis plays an essential role in fungal growth and competition, as well as for virulence. Our work reveals a novel post-translational regulation of autophagy initiated by a bacterial antibiotic. Rapamycin was shown to be a powerful modulator of bacteria–fungi interactions with potential importance in explaining microbial homeostasis in healthy plant microbiomes. The autophagic process provides novel possibilities and targets to biologically control pathogens.

scholarly journals EPHA2-dependent outcompetition of KRASG12D mutant cells by wild-type neighbors in the adult pancreas

2021 ◽  
Author(s):  
William Hill ◽  
Andreas Zaragkoulias ◽  
Beatriz Salvador-Barbero ◽  
Geraint J. Parfitt ◽  
Markella Alatsatianos ◽  
...  
Keyword(s):  
Wild Type ◽  
Mutant Cells

scholarly journals Colony spreading of the gliding bacterium Flavobacterium johnsoniae in the absence of the motility adhesin SprB

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keiko Sato ◽  
Masami Naya ◽  
Yuri Hatano ◽  
Yoshio Kondo ◽  
Mari Sato ◽  
...  
Keyword(s):  
Soft Agar ◽  
Gliding Motility ◽  
Wild Type ◽  
Initial Cell ◽  
Flavobacterium Johnsoniae ◽  
Seeking Behavior ◽  
Colony Spreading ◽  
Gliding Bacterium ◽  
Mutant Cells ◽  
Scanning Electron

AbstractColony spreading of Flavobacterium johnsoniae is shown to include gliding motility using the cell surface adhesin SprB, and is drastically affected by agar and glucose concentrations. Wild-type (WT) and ΔsprB mutant cells formed nonspreading colonies on soft agar, but spreading dendritic colonies on soft agar containing glucose. In the presence of glucose, an initial cell growth-dependent phase was followed by a secondary SprB-independent, gliding motility-dependent phase. The branching pattern of a ΔsprB colony was less complex than the pattern formed by the WT. Mesoscopic and microstructural information was obtained by atmospheric scanning electron microscopy (ASEM) and transmission EM, respectively. In the growth-dependent phase of WT colonies, dendritic tips spread rapidly by the movement of individual cells. In the following SprB-independent phase, leading tips were extended outwards by the movement of dynamic windmill-like rolling centers, and the lipoproteins were expressed more abundantly. Dark spots in WT cells during the growth-dependent spreading phase were not observed in the SprB-independent phase. Various mutations showed that the lipoproteins and the motility machinery were necessary for SprB-independent spreading. Overall, SprB-independent colony spreading is influenced by the lipoproteins, some of which are involved in the gliding machinery, and medium conditions, which together determine the nutrient-seeking behavior.

scholarly journals Targeting the DNA replication stress phenotype of KRAS mutant cancer cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tara Al Zubaidi ◽  
O. H. Fiete Gehrisch ◽  
Marie-Michelle Genois ◽  
Qi Liu ◽  
Shan Lu ◽  
...  
Keyword(s):  
Dna Replication ◽  
Single Molecule ◽  
Replication Stress ◽  
Proton Radiation ◽  
Wild Type ◽  
Cellular Effects ◽  
Proton Treatment ◽  
Dna Replication Stress ◽  
Fork Stalling ◽  
Mutant Cells

AbstractMutant KRAS is a common tumor driver and frequently confers resistance to anti-cancer treatments such as radiation. DNA replication stress in these tumors may constitute a therapeutic liability but is poorly understood. Here, using single-molecule DNA fiber analysis, we first characterized baseline replication stress in a panel of unperturbed isogenic and non-isogenic cancer cell lines. Correlating with the observed enhanced replication stress we found increased levels of cytosolic double-stranded DNA in KRAS mutant compared to wild-type cells. Yet, despite this phenotype replication stress-inducing agents failed to selectively impact KRAS mutant cells, which were protected by CHK1. Similarly, most exogenous stressors studied did not differentially augment cytosolic DNA accumulation in KRAS mutant compared to wild-type cells. However, we found that proton radiation was able to slow fork progression and preferentially induce fork stalling in KRAS mutant cells. Proton treatment also partly reversed the radioresistance associated with mutant KRAS. The cellular effects of protons in the presence of KRAS mutation clearly contrasted that of other drugs affecting replication, highlighting the unique nature of the underlying DNA damage caused by protons. Taken together, our findings provide insight into the replication stress response associated with mutated KRAS, which may ultimately yield novel therapeutic opportunities.

Yeast dom34 Mutants Are Defective in Multiple Developmental Pathways and Exhibit Decreased Levels of Polyribosomes

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 45-56
Author(s):  
Luther Davis ◽  
JoAnne Engebrecht
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Heterologous Expression ◽  
Protein Translation ◽  
Developmental Pathways ◽  
G1 Phase ◽  
Growth Defect ◽  
Wild Type ◽  
Drosophila Homolog ◽  
Mutant Cells

Abstract The DOM34 gene of Saccharomyces cerevisiae is similar togenes found in diverse eukaryotes and archaebacteria. Analysis of dom34 strains shows that progression through the G1 phase of the cell cycle is delayed, mutant cells enter meiosis aberrantly, and their ability to form pseudohyphae is significantly diminished. RPS30A, which encodes ribosomal protein S30, was identified in a screen for high-copy suppressors of the dom34Δ growth defect. dom34Δ mutants display an altered polyribosome profile that is rescued by expression of RPS30A. Taken together, these data indicate that Dom34p functions in protein translation to promote G1 progression and differentiation. A Drosophila homolog of Dom34p, pelota, is required for the proper coordination of meiosis and spermatogenesis. Heterologous expression of pelota in dom34Δ mutants restores wild-type growth and differentiation, suggesting conservation of function between the eukaryotic members of the gene family.

scholarly journals Mitotic Recombination and Adaptive Genomic Changes in Human Pathogenic Fungi

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 901 ◽  
Author(s):  
Asiya Gusa ◽  
Sue Jinks-Robertson
Keyword(s):  
Fungal Pathogens ◽  
Repetitive Sequences ◽  
Pathogenic Fungi ◽  
Genetic Alterations ◽  
Fungal Species ◽  
Chronic Infections ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genomic Changes ◽  
Break Site ◽  
Repair Mechanisms

Genome rearrangements and ploidy alterations are important for adaptive change in the pathogenic fungal species Candida and Cryptococcus, which propagate primarily through clonal, asexual reproduction. These changes can occur during mitotic growth and lead to enhanced virulence, drug resistance, and persistence in chronic infections. Examples of microevolution during the course of infection were described in both human infections and mouse models. Recent discoveries defining the role of sexual, parasexual, and unisexual cycles in the evolution of these pathogenic fungi further expanded our understanding of the diversity found in and between species. During mitotic growth, damage to DNA in the form of double-strand breaks (DSBs) is repaired, and genome integrity is restored by the homologous recombination and non-homologous end-joining pathways. In addition to faithful repair, these pathways can introduce minor sequence alterations at the break site or lead to more extensive genetic alterations that include loss of heterozygosity, inversions, duplications, deletions, and translocations. In particular, the prevalence of repetitive sequences in fungal genomes provides opportunities for structural rearrangements to be generated by non-allelic (ectopic) recombination. In this review, we describe DSB repair mechanisms and the types of resulting genome alterations that were documented in the model yeast Saccharomyces cerevisiae. The relevance of similar recombination events to stress- and drug-related adaptations and in generating species diversity are discussed for the human fungal pathogens Candida albicans and Cryptococcus neoformans.

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