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1.
New Phytol ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34761375

RESUMO

During plant pathogenic fungi and host plants interactions, numerous pathogen-derived proteins are secreted resulting in the activation of the unfolded protein response pathway (UPR). For efficient trafficking of secretory proteins, including those important in disease progression, the cytoplasmic coat protein complex-II (COPII) exhibits a multifunctional role whose elucidation remains limited. Here, we discovered that the COPII cargo receptor MoErv29 functions as a target of MoHac1, a previously identified transcription factor of the UPR pathway. Deletion of MoERV29 severely affected the vegetative growth, conidiation, and biotrophic invasion of the fungus in susceptible rice hosts. We demonstrated that MoErv29 is required for the delivery of secreted proteins through recognition and binding of the amino-terminal tripeptide motifs following the signal peptide. By using bioinformatics analysis, we predicted a cargo spectrum of MoErv29 and found that MoErv29 is required for the secretion of many proteins, including extracellular laccases and apoplastic effectors. This secretion is mediated through the conventional ER-Golgi secretion pathway and is important to confer host recognition and disease resistance. Taken together, our results revealed how MoErv29 operates on effector secretion, and our findings provided a critical link between COPII vesicle trafficking and the UPR pathway.

2.
FEBS J ; 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34453409

RESUMO

Magnaporthe oryzae is a hemibiotrophic fungus that also needs host nutrients for propagation during infection. During its interaction with rice, reactive oxygen species (ROS) mediate important signaling reactions impacting both the pathogen and the host. In M. oryzae, the accumulation of ROS is important for the formation and maturation of the infectious structure appressorium. On the other hand, upon M. oryzae infection, rice generates further ROS to restrict invasive hyphae (IH) spreading. Despite ROS receptors remaining to be identified, M. oryzae recruits several strategies to respond and suppress ROS accumulation through the secretion of various effector molecules. These findings suggest that the balance between the generation and scavenging of ROS is sophisticatedly controlled during M. oryzae-rice interaction. In this review, we discuss advances to understand the regulation mechanisms for the generation, accumulation, and transduction of ROS.

3.
Environ Microbiol ; 23(9): 5463-5480, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34288342

RESUMO

Pyricularia oryzae is a multi-host pathogen causing cereal disease, including the devastating rice blast. Panicle blast is a serious stage, leading to severe yield loss. Thirty-one isolates (average 4.1%) were collected from the rice panicle lesions at nine locations covering Jiangsu province from 2010 to 2017. These isolates were characterized as Pyricularia sp. jiangsuensis distinct from known Pyricularia species. The representative strain 18-2 can infect rice panicle, root and five kinds of grasses. Intriguingly, strain 18-2 can co-infect rice leaf with P. oryzae Guy11. The whole genome of P. sp. jiangsuensis 18-2 was sequenced. Nine effectors were distributed in translocation or inversion region, which may link to the rapid evolution of effectors. Twenty-one homologues of known blast-effectors were identified in strain 18-2, seven effectors including the homologues of SLP1, BAS2, BAS113, CDIP2/3, MoHEG16 and Avr-Pi54, were upregulated in the sample of inoculated panicle with strain 18-2 at 24 hpi compared with inoculation at 8 hpi. Our results provide evidences that P. sp. jiangsuensis represents an addition to the mycobiota of blast disease. This study advances our understanding of the pathogenicity of P. sp. jiangsuensis to hosts, which sheds new light on the adaptability in the co-evolution of pathogen and host.

4.
Inflammopharmacology ; 29(5): 1587-1601, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34322786

RESUMO

Erlotinib (ERL) is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) of pancreatic cancer (PC). However, the clinical efficacy of ERL is limited due to the activation of alternative pathways that bypass the EGFR signaling. Kaempferol (KAE), a natural flavonoid compound, has been reported to possess potent anti-tumor and anti-inflammatory properties, and in this study, we aimed at identifying the sensitization effect of KAE on ERL monotherapy in PC cells and mouse models. Briefly, the CCK-8, colony formation, and flow cytometry were used to assess the proliferation and apoptosis of two PC cell lines in response to a treatment combination of KAE and ERL. Additionally, the drug-disease targets and related anti-PC mechanisms of KAE and ERL were predicted with a network pharmacology method. The survival outcome for PC patients with EGFR differential expression was evaluated through survival analysis. The molecular docking technique predicted the affinity between KAE and EGFR. Moreover, western blot (WB) and immunohistochemistry (IHC) analyses were applied to verify the expression levels of related proteins. As a result, in vitro results showed that the combination of KAE and ERL significantly inhibited cell proliferation and promoted cell apoptosis compared to that with ERL alone. Network pharmacology results demonstrated that KAE sensitized PC to ERL treatment may likely be related to the PI3K/AKT signaling pathway and EGFR TKI resistance. Survival analysis illustrated that PC patients with high expression of EGFR had a relative lower survival rate. Molecular docking results further suggested that KAE had a high binding affinity of - 8.9 kcal/mol with EGFR. WB results indicated that the combination of KAE and ERL dramatically downregulated the expression levels of p-EGFR, p-AKT, p-ERK1/2, and Bcl-2, and upregulated the expression levels of cleaved caspase-9, cleaved PARP, and Bax. The in vivo results revealed that treatment combination of KAE and ERL further reduced the volume and weight of subcutaneous grafted tumors. IHC results confirmed the WB results. These data imply that KAE may be a valid therapeutic candidate to potentiate PC cell sensitivity to ERL via inhibiting PI3K/AKT and EGFR signaling.

5.
J Ginseng Res ; 45(4): 465-472, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34295206

RESUMO

Background: Ginseng can help regulate brain excitability, promote learning and memory, and resist cerebral ischemia in the central nervous system. Ginsenosides are the major effective compounds of Ginseng, but their protein targets in the brain have not been determined. Methods: We screened proteins that interact with the main components of ginseng (ginsenosides) by affinity chromatography and identified the 14-3-3 ζ protein as a potential target of ginsenosides in brain tissues. Results: Biolayer interferometry (BLI) analysis showed that 20(S)-protopanaxadiol (PPD), a ginseng saponin metabolite, exhibited the highest direct interaction to the 14-3-3 ζ protein. Subsequently, BLI kinetics analysis and isothermal titration calorimetry (ITC) assay showed that PPD specifically bound to the 14-3-3 ζ protein. The cocrystal structure of the 14-3-3 ζ protein-PPD complex showed that the main interactions occurred between the residues R56, R127, and Y128 of the 14-3-3 ζ protein and a portion of PPD. Moreover, mutating any of the above residues resulted in a significant decrease of affinity between PPD and the 14-3-3 ζ protein. Conclusion: Our results indicate the 14-3-3 ζ protein is the target of PPD, a ginsenoside metabolite. Crystallographic and mutagenesis studies suggest a direct interaction between PPD and the 14-3-3 ζ protein. This finding can help in the development of small-molecular compounds that bind to the 14-3-3 ζ protein on the basis of the structure of dammarane-type triterpenoid.

6.
PLoS Pathog ; 17(6): e1009657, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34133468

RESUMO

GTP-binding protein (G-protein) and regulator of G-protein signaling (RGS) mediated signal transduction are critical in the growth and virulence of the rice blast pathogen Magnaporthe oryzae. We have previously reported that there are eight RGS and RGS-like proteins named MoRgs1 to MoRgs8 playing distinct and shared regulatory functions in M. oryzae and that MoRgs1 has a more prominent role compared to others in the fungus. To further explore the unique regulatory mechanism of MoRgs1, we screened a M. oryzae cDNA library for genes encoding MoRgs1-interacting proteins and identified MoCkb2, one of the two regulatory subunits of the casein kinase (CK) 2 MoCk2. We found that MoCkb2 and the sole catalytic subunit MoCka1 are required for the phosphorylation of MoRgs1 at the plasma membrane (PM) and late endosome (LE). We further found that an endoplasmic reticulum (ER) membrane protein complex (EMC) subunit, MoEmc2, modulates the phosphorylation of MoRgs1 by MoCk2. Interestingly, this phosphorylation is also essential for the GTPase-activating protein (GAP) function of MoRgs1. The balance among MoRgs1, MoCk2, and MoEmc2 ensures normal operation of the G-protein MoMagA-cAMP signaling required for appressorium formation and pathogenicity of the fungus. This has been the first report that an EMC subunit is directly linked to G-protein signaling through modulation of an RGS-casein kinase interaction.


Assuntos
Ascomicetos/metabolismo , Ascomicetos/patogenicidade , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Parasita/fisiologia , Virulência/fisiologia , Caseína Quinases/metabolismo , Fosforilação , Transdução de Sinais/fisiologia
7.
Nat Commun ; 12(1): 2451, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33907187

RESUMO

Many pathogens infect hosts through specific organs, such as Ustilaginoidea virens, which infects rice panicles. Here, we show that a microbe-associated molecular pattern (MAMP), Ser-Thr-rich Glycosyl-phosphatidyl-inositol-anchored protein (SGP1) from U. virens, induces immune responses in rice leaves but not panicles. SGP1 is widely distributed among fungi and acts as a proteinaceous, thermostable elicitor of BAK1-dependent defense responses in N. benthamiana. Plants specifically recognize a 22 amino acid peptide (SGP1 N terminus peptide 22, SNP22) in its N-terminus that induces cell death, oxidative burst, and defense-related gene expression. Exposure to SNP22 enhances rice immunity signaling and resistance to infection by multiple fungal and bacterial pathogens. Interestingly, while SGP1 can activate immune responses in leaves, SGP1 is required for U. virens infection of rice panicles in vivo, showing it contributes to the virulence of a panicle adapted pathogen.


Assuntos
Proteínas Fúngicas/imunologia , Hypocreales/patogenicidade , Oryza/imunologia , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/imunologia , Sequência de Aminoácidos , Morte Celular/genética , Morte Celular/imunologia , Proteínas Fúngicas/genética , Regulação da Expressão Gênica , Glicosilfosfatidilinositóis/química , Glicosilfosfatidilinositóis/metabolismo , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Hypocreales/imunologia , Inflorescência/genética , Inflorescência/imunologia , Inflorescência/microbiologia , Oryza/genética , Oryza/microbiologia , Padrões Moleculares Associados a Patógenos/imunologia , Padrões Moleculares Associados a Patógenos/metabolismo , Peptídeos/genética , Peptídeos/imunologia , Células Vegetais/imunologia , Células Vegetais/patologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Folhas de Planta/genética , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Virulência
8.
New Phytol ; 230(2): 720-736, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33423301

RESUMO

Plant pathogens exploit the extracellular matrix (ECM) to inhibit host immunity during their interactions with the host. The formation of ECM involves a series of continuous steps of vesicular transport events. To understand how such vesicle trafficking impacts ECM and virulence in the rice blast fungus Magnaporthe oryzae, we characterised MoSwa2, a previously identified actin-regulating kinase MoArk1 interacting protein, as an orthologue of the auxilin-like clathrin uncoating factor Swa2 of the budding yeast Saccharomyces cerevisiae. We found that MoSwa2 functions as an uncoating factor of the coat protein complex II (COPII) via an interaction with the COPII subunit MoSec24-2. Loss of MoSwa2 led to a deficiency in the secretion of extracellular proteins, resulting in both restricted growth of invasive hyphae and reduced inhibition of host immunity. Additionally, extracellular fluid (ECF) proteome analysis revealed that MoSwa2-regulated extracellular proteins include many redox proteins such as the berberine bridge enzyme-like (BBE-like) protein MoSef1. We further found that MoSef1 functions as an apoplastic virulent factor that inhibits the host immune response. Our studies revealed a novel function of a COPII uncoating factor in vesicular transport that is critical in the suppression of host immunity and pathogenicity of M. oryzae.


Assuntos
Magnaporthe , Oryza , Ascomicetos , Auxilinas , Clatrina , Proteínas Fúngicas , Doenças das Plantas , Virulência
9.
PLoS Pathog ; 17(1): e1009080, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33411855

RESUMO

The fungal cell wall plays an essential role in maintaining cell morphology, transmitting external signals, controlling cell growth, and even virulence. Relaxation and irreversible stretching of the cell wall are the prerequisites of cell division and development, but they also inevitably cause cell wall stress. Both Mitotic Exit Network (MEN) and Cell Wall Integrity (CWI) are signaling pathways that govern cell division and cell stress response, respectively, how these pathways cross talk to govern and coordinate cellular growth, development, and pathogenicity remains not fully understood. We have identified MoSep1, MoDbf2, and MoMob1 as the conserved components of MEN from the rice blast fungus Magnaporthe oryzae. We have found that blocking cell division results in abnormal CWI signaling. In addition, we discovered that MoSep1 targets MoMkk1, a conserved key MAP kinase of the CWI pathway, through protein phosphorylation that promotes CWI signaling. Moreover, we provided evidence demonstrating that MoSep1-dependent MoMkk1 phosphorylation is essential for balancing cell division with CWI that maintains the dynamic stability required for virulence of the blast fungus.


Assuntos
Parede Celular/fisiologia , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Magnaporthe/patogenicidade , Mitose , Oryza/microbiologia , Doenças das Plantas/microbiologia , Parede Celular/microbiologia , Proteínas Fúngicas/genética , Fosforilação , Transdução de Sinais
10.
Environ Microbiol ; 23(2): 791-809, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32564502

RESUMO

The type 2A (PP2A) and type 2A-like (PP4 and PP6) serine/threonine phosphatases participate in a variety of cellular processes, such as cell cycle progression, signal transduction and apoptosis. Previously, we reported that the PP6 catalytic subunit MoPpe1, which interacts with and is suppressed by type 2A associated protein of 42 kDa (MoTap42), an essential protein involved in the target of rapamycin (TOR) signalling pathway, has important roles in development, virulence and activation of the cell wall integrity (CWI) pathway in the rice blast fungus Magnaporthe oryzae. Here, we show that Tap42-interacting protein 41 (MoTip41) mediates crosstalk between the TOR and CWI signalling pathways; and participates in the TOR pathway via interaction with MoPpe1, but not MoTap42. The deletion of MoTIP41 resulted in disruption of CWI signalling, autophagy, vegetative growth, appressorium function and plant infection, as well as increased sensitivity to rapamycin. Further investigation revealed that MoTip41 modulates activation of the CWI pathway in response to infection by interfering with the interaction between MoTap42 and MoPpe1. These findings enhance our understanding of how crosstalk between TOR and CWI signalling modulates the development and pathogenicity of M. oryzae.


Assuntos
Ascomicetos/metabolismo , Parede Celular/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Sirolimo/metabolismo , Ascomicetos/patogenicidade , Autofagia , Proteínas de Ciclo Celular/metabolismo , Proteínas Fúngicas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Oryza/microbiologia , Fosfoproteínas Fosfatases/genética , Doenças das Plantas/microbiologia , Transdução de Sinais/fisiologia , Virulência
11.
Environ Microbiol ; 23(2): 774-790, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32431008

RESUMO

Mitochondrial quality and quantity are essential for a cell to maintain normal cellular functions. Our previous study revealed that the transcription factor MoMsn2 plays important roles in the development and virulence of Magnaporthe oryzae. However, to date, no study has reported its underlying regulatory mechanism in phytopathogens. Here, we explored the downstream target genes of MoMsn2 using a chromatin immunoprecipitation sequencing (ChIP-Seq) approach. In total, 332 target genes and five putative MoMsn2-binding sites were identified. The 332 genes exhibited a diverse array of functions and the highly represented were genes involved in metabolic and catalytic processes. Based on the ChIP-Seq data, we found that MoMsn2 plays a role in maintaining mitochondrial morphology, likely by targeting a number of mitochondria-related genes. Further investigation revealed that MoMsn2 targets the putative 3-methylglutaconyl-CoA hydratase-encoding gene (MoAUH1) to control mitochondrial morphology and mitophagy, which are critical for the infectious growth of the pathogen. Meanwhile, the deletion of MoAUH1 resulted in phenotypes similar to the ΔMomsn2 mutant in mitochondrial morphology, mitophagy and virulence. Overall, our results provide evidence for the regulatory mechanisms of MoMsn2, which targets MoAUH1 to modulate its transcript levels, thereby disturbing the mitochondrial fusion/fission balance. This ultimately affects the development and virulence of M. oryzae.


Assuntos
Ascomicetos , Hidroliases/genética , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/genética , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/patogenicidade , Sítios de Ligação/genética , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/genética , Mitofagia/genética , Fenótipo , Doenças das Plantas/microbiologia , Fatores de Transcrição/metabolismo , Virulência/genética
12.
Elife ; 92020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33275098

RESUMO

The production of reactive oxygen species (ROS) is a ubiquitous defense response in plants. Adapted pathogens evolved mechanisms to counteract the deleterious effects of host-derived ROS and promote infection. How plant pathogens regulate this elaborate response against ROS burst remains unclear. Using the rice blast fungus Magnaporthe oryzae, we uncovered a self-balancing circuit controlling response to ROS in planta and virulence. During infection, ROS induces phosphorylation of the high osmolarity glycerol pathway kinase MoOsm1 and its nuclear translocation. There, MoOsm1 phosphorylates transcription factor MoAtf1 and dissociates MoAtf1-MoTup1 complex. This releases MoTup1-mediated transcriptional repression on oxidoreduction-pathway genes and activates the transcription of MoPtp1/2 protein phosphatases. In turn, MoPtp1/2 dephosphorylate MoOsm1, restoring the circuit to its initial state. Balanced interactions among proteins centered on MoOsm1 provide a means to counter host-derived ROS. Our findings thereby reveal new insights into how M. oryzae utilizes a phosphor-regulatory circuitry to face plant immunity during infection.


Assuntos
Ascomicetos/enzimologia , Proteínas Fúngicas/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação Fúngica da Expressão Gênica/fisiologia , Oryza/microbiologia , Espécies Reativas de Oxigênio , Adaptação Fisiológica , Ascomicetos/genética , Proteínas Fúngicas/genética , Oryza/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Fosforilação , Doenças das Plantas/microbiologia
13.
ACS Omega ; 5(31): 19565-19578, 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32803051

RESUMO

Coalbed is the carrier for coalbed methane (CBM) enrichment and migration. The pore structure characteristics of coal and their main geological controlling factors are critical to the exploration and development of CBM. In this paper, 20 coal samples were collected from eastern Yunnan and western Guizhou, China. Based on vitrinite reflectance, proximate analysis, maceral analysis, and low-temperature N2 adsorption/desorption (LT-N2GA) experiments, the hysteresis coefficient of low-temperature N2 desorption was proposed, the types of pore structure were identified, and the effects of coal facies and rank on the pore structure were revealed. The results show that the R o,max values of the 20 coal samples are between 0.74 and 3.38%, which belong to medium- and high-rank coal. In the coal macerals, the vitrinite is mainly collodetrinite. The inertinite is dominated by semifusinite, and some coal samples contain exinite. The coal samples investigated can be divided into two types. Type A samples mainly contain open pores, while type B samples are rich in bottle-shaped pores. Compared with type A coal samples, type B samples have the characteristics of smaller total pore volume (TPV), smaller average pore diameter (APD), larger specific surface area (SSA), and larger hysteresis coefficient. The coal samples are located in three regions of different coal facies, including low-level swamp (reed) facies, wetland herbaceous swamp facies, and wet forest swamp facies. The tissue preservation index (TPI) values of most coal samples are less than unity, which indicates that herbaceous plants have absolute dominance in the coal-forming plants in eastern Yunnan and western Guizhou. The maximum vitrinite reflectance (R o,max), gelification index (GI), TPI, vitrinite content (V), inertinite content (I), Barrett-Joyner-Halenda pore volume (V BJH), Brunauer-Emmett-Teller SSA (S BET), and low-temperature N2 desorption total hysteresis coefficient (H t) were clustered using the R-type cluster analysis method. It is found that TPI is the main controlling factor of the pore structure of type A coal samples, while the pore structure of type B coal samples are jointly controlled by TPI and coal rank. Type B coal samples are mainly located in Zhuzang and Laochang high-rank coal research areas, while the distribution of type A coal samples is mainly in other medium-high-rank coal research areas. These results will contribute to the exploration and development of CBM and also guide the study of pore structures of other unconventional gas reservoirs.

14.
Artigo em Inglês | MEDLINE | ID: mdl-32656093

RESUMO

Membrane vesicles are considered virulence cargoes as they carry capsular and melanin components whose secretory transport is critical for the virulence of the human fungal pathogen Cryptococcus species. However, other components of the vesicles and their function in the growth and virulence of the fungus remain unclear. We have previously found that the cryptococcal intersectin protein Cin1 governs a unique Cin1-Wsp1-Cdc42 endocytic pathway required for intracellular transport and virulence. Using RNA sequencing, we compared the profiles of extracellular RNA (exRNA), including microRNA (miRNA), small interference RNA (siRNA), long noncoding RNA (lncRNA), and messenger RNA (mRNA) between the wild-type (WT), and derived Δcin1 mutant strains of Cryptococcus deneoformans. Seven hundred twelve miRNAs and 88 siRNAs were identified from WT, whereas 799 miRNAs and 66 siRNAs were found in Δcin1. Also, 572 lncRNAs and 7,721 mRNAs were identified from WT and 584 lncRNAs and 7,703 mRNAs from Δcin1. Differential expression analysis revealed that the disruption of CIN1 results in many important cellular changes, including those in exRNA expression, transport, and function. First, for miRNA target genes, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that cellular processes, components, and macromolecular functions are the most affected pathways. A higher number of genes were involved in the intracellular transport of endocytosis. Second, the results of GO term and KEGG analysis of differentially expressed lncRNA target genes and mRNA genes were consistent with those of miRNA targets. In particular, protein export is the topmost affected pathway among lncRNA target genes and one of the affected pathways among mRNA genes. The result of quantitative real-time reverse transcription PCR (qRT-PCR) from 12 mRNAs tested is largely agreeable with that of RNA-Seq. Taken together, our studies provide a comprehensive reference that Cryptococcus secretes abundant RNAs and that Cin1 plays a critical role in regulating their secretion. Given the growing clinical importance of exRNAs, our studies illuminate the significance of exploring this cutting-edge technology in studies of cryptococcal pathogenesis for the discovery of novel therapeutic strategies.


Assuntos
Cryptococcus , Proteínas Fúngicas/metabolismo , MicroRNAs , Proteínas Associadas aos Microtúbulos/metabolismo , RNA Longo não Codificante , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , MicroRNAs/genética , Transcriptoma
15.
Science ; 368(6494): 988-993, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32467388

RESUMO

A positive feedback mechanism between tropical cyclones (TCs) and climate warming can be seen by examining TC-induced energy and potential vorticity (PV) changes of oceanic geostrophic eddies. We found that substantial dissipation of eddies, with a strong bias toward dissipation of anticyclonic eddies, is directly linked to TC activity. East of Taiwan, where TCs show a remarkable intensifying trend in recent decades, the ocean exhibits a corresponding upward trend of positive PV anomalies. Carried westward by eddies, increasing numbers of positive PV anomalies impinge on the Kuroshio current, causing the mean current to accelerate downstream. This acts in opposition to decreasing basin-scale wind stress and has a potentially important warming impact on the extratropical ocean and climate.

16.
mBio ; 11(2)2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32209696

RESUMO

The appressoria that are generated by the rice blast fungus Magnaporthe oryzae in response to surface cues are important for successful colonization. Previous work showed that regulators of G-protein signaling (RGS) and RGS-like proteins play critical roles in appressorium formation. However, the mechanisms by which these proteins orchestrate surface recognition for appressorium induction remain unclear. Here, we performed comparative transcriptomic studies of ΔMorgs mutant and wild-type strains and found that M. oryzae Aa91 (MoAa91), a homolog of the auxiliary activity family 9 protein (Aa9), was required for surface recognition of M. oryzae We found that MoAA91 was regulated by the MoMsn2 transcription factor and that its disruption resulted in defects in both appressorium formation on the artificial inductive surface and full virulence of the pathogen. We further showed that MoAa91 was secreted into the apoplast space and was capable of competing with the immune receptor chitin elicitor-binding protein precursor (CEBiP) for chitin binding, thereby suppressing chitin-induced plant immune responses. In summary, we have found that MoAa91 is a novel signaling molecule regulated by RGS and RGS-like proteins and that MoAa91 not only governs appressorium development and virulence but also functions as an effector to suppress host immunity.IMPORTANCE The rice blast fungus Magnaporthe oryzae generates infection structure appressoria in response to surface cues largely due to functions of signaling molecules, including G-proteins, regulators of G-protein signaling (RGS), mitogen-activated protein (MAP) kinase pathways, cAMP signaling, and TOR signaling pathways. M. oryzae encodes eight RGS and RGS-like proteins (MoRgs1 to MoRgs8), and MoRgs1, MoRgs3, MoRgs4, and MoRgs7 were found to be particularly important in appressorium development. To explore the mechanisms by which these proteins regulate appressorium development, we have performed a comparative in planta transcriptomic study and identified an auxiliary activity family 9 protein (Aa9) homolog that we named MoAa91. We showed that MoAa91 was secreted from appressoria and that the recombinant MoAa91 could compete with a chitin elicitor-binding protein precursor (CEBiP) for chitin binding, thereby suppressing chitin-induced plant immunity. By identifying MoAa91 as a novel signaling molecule functioning in appressorium development and an effector in suppressing host immunity, our studies revealed a novel mechanism by which RGS and RGS-like proteins regulate pathogen-host interactions.


Assuntos
Ascomicetos/patogenicidade , Quitina/metabolismo , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Oryza/imunologia , Imunidade Vegetal , Ascomicetos/genética , Proteínas Fúngicas/genética , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Oryza/microbiologia , Doenças das Plantas/microbiologia , Transdução de Sinais , Virulência
17.
Fungal Genet Biol ; 137: 103349, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32006681

RESUMO

MicroRNAs (miRNAs) play important roles in various cellular growth and developmental processes through post-transcriptional gene regulation via mRNA cleavage and degradation and the inhibition of protein translation. To explore if miRNAs play a role in appressoria formation and virulence that are also governed by the regulators of G-protein signaling (RGS) proteins in the rice blast fungus Magnaporthe oryzae, we have compared small RNA (sRNA) production between several ΔMorgs mutant and the wild-type strains. We have identified sRNA236 as a microRNA-like milR236 that targets the encoding sequence of MoHat1, a histone acetyltransferase type B catalytic subunit involved in appressorium function and virulence. We have also found that milR236 overexpression induces delayed appressorium formation and virulence attenuation, similar to those displayed by the ΔMohat1 mutant strain. Moreover, we have shown that the transcription factor MoMsn2 binds to the promoter sequence of milR236 to further suppress MoHAT1 transcription and MoHat1-regulated appressorium formation and virulence. In summary, by identifying a novel regulatory role of sRNA in the blast fungus, our studies reveal a new paradigm in the multifaceted regulatory pathways that govern the appressorium formation and virulence of M. oryzae.


Assuntos
Ascomicetos/genética , Histona Acetiltransferases/genética , Ascomicetos/metabolismo , Ascomicetos/patogenicidade , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica/genética , Histona Acetiltransferases/metabolismo , Magnaporthe/genética , Magnaporthe/patogenicidade , MicroRNAs/genética , MicroRNAs/metabolismo , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais/genética , Esporos Fúngicos/crescimento & desenvolvimento , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Virulência
18.
Proc Natl Acad Sci U S A ; 117(2): 872-876, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31888984

RESUMO

Virtually all proton-pumping terminal respiratory oxygen reductases are members of the heme-copper oxidoreductase superfamily. Most of these enzymes use reduced cytochrome c as a source of electrons, but a group of enzymes have evolved to directly oxidize membrane-bound quinols, usually menaquinol or ubiquinol. All of the quinol oxidases have an additional transmembrane helix (TM0) in subunit I that is not present in the related cytochrome c oxidases. The current work reports the 3.6-Å-resolution X-ray structure of the cytochrome aa 3 -600 menaquinol oxidase from Bacillus subtilis containing 1 equivalent of menaquinone. The structure shows that TM0 forms part of a cleft to accommodate the menaquinol-7 substrate. Crystals which have been soaked with the quinol-analog inhibitor HQNO (N-oxo-2-heptyl-4-hydroxyquinoline) or 3-iodo-HQNO reveal a single binding site where the inhibitor forms hydrogen bonds to amino acid residues shown previously by spectroscopic methods to interact with the semiquinone state of menaquinone, a catalytic intermediate.


Assuntos
Bacillus subtilis/metabolismo , Cobre/química , Complexo IV da Cadeia de Transporte de Elétrons/química , Heme/química , Hidroquinonas/química , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Grupo dos Citocromos b/química , Transporte de Elétrons , Ligação de Hidrogênio , Modelos Moleculares , Naftóis/metabolismo , Oxirredutases , Conformação Proteica , Subunidades Proteicas/química , Bombas de Próton/química , Bombas de Próton/metabolismo , Terpenos/metabolismo , Vitamina K 2/análogos & derivados , Vitamina K 2/química
19.
Autophagy ; 16(5): 900-916, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31313634

RESUMO

Cells are faced with various stresses during their growth and development, and autophagy is a degradative process in which cells can break down their own components to recycle macromolecules and provide energy under these stresses. For pathogenic fungi that utilize cell wall as the first barrier against external stress, the cell wall integrity (CWI) pathway also provides an essential role in responding to these stresses. However, the specific connection between autophagy and CWI remains elusive in either the model fungi including budding yeast Saccharomyces cerevisiae or the rice blast fungus Magnaporthe oryzae. Here, we provided evidence that the endoplasmic reticulum (ER) stress is highly induced during M. oryzae infection and that CWI MAP kinase kinase MoMkk1 (S. cerevisiae Mkk1/2 homolog) was subject to phosphorylation regulation by MoAtg1, the only identified kinase in the core autophagy machinery. We also identified MoMkk1 serine 115 as the MoAtg1-dependent phosphorylation site and this phosphorylation could activate CWI, similar to that by the conserved MAP kinase kinase kinase MoMck1 (S. cerevisiae Bck1 homolog). Together with the first report of MoMkk1 subjects to phosphorylation regulation by MoAtg1, we revealed a new mechanism by which autophagy coordinates with CWI signaling under ER stress, and this MoAtg1-dependent MoMkk1 phosphorylation is essential for the pathogenicity of M. oryzae.Abbreviations: A/Ala: alanine; Atg: autophagy-related; Bck1: bypass of C kinase 1; co-IP: co-immunoprecipitation; CWI: cell wall integrity;DTT: dithiothreitol; ER: endoplasmic reticulum; GFP: green fluorescent protein; Mo: Magnaporthe oryzae; MAPK: mitogen-activated protein kinase; Mkk1: mitogen-activated protein kinase-kinase 1; MS: mass spectrometry; PAS: phagophore assembly site; RFP: red fluorescent protein; RT: room temperature; S/Ser: serine; Slt2: suppressor of the lytic phenotype 2; T/Thr: threonine; UPR: unfolded protein response; Y2H: yeast two-hybrid screen.


Assuntos
Ascomicetos/metabolismo , Autofagia/fisiologia , Parede Celular/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Autofagia/genética , Proteínas Fúngicas/metabolismo , Magnaporthe/genética , Oryza/microbiologia , Doenças das Plantas/microbiologia , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais/fisiologia , Virulência/fisiologia
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