A Novel, Small Cysteine-Rich Effector, RsSCR10 in Rhizoctonia solani Is Sufficient to Trigger Plant Cell Death

The necrotrophic phytopathogen Rhizoctonia solani (R. solani) is a fungus that causes disease in a wide range of plant species. Fungal genomes encode abundant, small cysteine-rich (SCR) secreted proteins, and the probable importance of these to pathogenesis has been highlighted in various pathogens. However, there are currently no reports of an R. solani SCR-secreted protein with evidential elicitor activity. In this study, the molecular function of 10 SCR-secreted protein genes from R. solani was explored by agroinfiltration into Nicotiana benthamiana (N. benthamiana) leaves, and a novel SCR protein RsSCR10 was identified that triggered cell death and oxidative burst in tobacco. RsSCR10 comprises 84 amino acids, including a signal peptide (SP) of 19 amino acids that is necessary for RsSCR10 to induce tobacco cell death. Elicitation of cell death by RsSCR10 was dependent on Hsp90 but not on RAR1, proving its effector activity. Two cysteine residues have important effects on the function of RsSCR10 in inducing cell death. Furthermore, RsSCR10 showed cross-interaction with five rice molecules, and the inferred functions of these rice proteins suggest they are instrumental in how the host copes with adversity. Overall, this study demonstrates that RsSCR10 is a potential effector that has a critical role in R. solani AG1 IA-host interactions.

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Comparative genome analyses of four rice-infecting Rhizoctonia solani isolates reveal extensive enrichment of homogalacturonan modification genes

BMC Genomics ◽

10.1186/s12864-021-07549-7 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Da-Young Lee ◽

Jongbum Jeon ◽

Ki-Tae Kim ◽

Kyeongchae Cheong ◽

Hyeunjeong Song ◽

...

Keyword(s):

Rhizoctonia Solani ◽

Single Molecule ◽

De Novo ◽

Average Length ◽

Gene Clusters ◽

Anastomosis Group ◽

Secreted Proteins ◽

Geographical Regions ◽

Wide Range ◽

Fungal Genomes

Abstract Background Plant pathogenic isolates of Rhizoctonia solani anastomosis group 1-intraspecific group IA (AG1-IA) infect a wide range of crops causing diseases such as rice sheath blight (ShB). ShB has become a serious disease in rice production worldwide. Additional genome sequences of the rice-infecting R. solani isolates from different geographical regions will facilitate the identification of important pathogenicity-related genes in the fungus. Results Rice-infecting R. solani isolates B2 (USA), ADB (India), WGL (India), and YN-7 (China) were selected for whole-genome sequencing. Single-Molecule Real-Time (SMRT) and Illumina sequencing were used for de novo sequencing of the B2 genome. The genomes of the other three isolates were then sequenced with Illumina technology and assembled using the B2 genome as a reference. The four genomes ranged from 38.9 to 45.0 Mbp in size, contained 9715 to 11,505 protein-coding genes, and shared 5812 conserved orthogroups. The proportion of transposable elements (TEs) and average length of TE sequences in the B2 genome was nearly 3 times and 2 times greater, respectively, than those of ADB, WGL and YN-7. Although 818 to 888 putative secreted proteins were identified in the four isolates, only 30% of them were predicted to be small secreted proteins, which is a smaller proportion than what is usually found in the genomes of cereal necrotrophic fungi. Despite a lack of putative secondary metabolite biosynthesis gene clusters, the rice-infecting R. solani genomes were predicted to contain the most carbohydrate-active enzyme (CAZyme) genes among all 27 fungal genomes used in the comparative analysis. Specifically, extensive enrichment of pectin/homogalacturonan modification genes were found in all four rice-infecting R. solani genomes. Conclusion Four R. solani genomes were sequenced, annotated, and compared to other fungal genomes to identify distinctive genomic features that may contribute to the pathogenicity of rice-infecting R. solani. Our analyses provided evidence that genomic conservation of R. solani genomes among neighboring AGs was more diversified than among AG1-IA isolates and the presence of numerous predicted pectin modification genes in the rice-infecting R. solani genomes that may contribute to the wide host range and virulence of this necrotrophic fungal pathogen.

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Characterization of Cell-Death-Inducing Members of the Pectate Lyase Gene Family in Phytophthora capsici and Their Contributions to Infection of Pepper

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-11-14-0352-r ◽

2015 ◽

Vol 28 (7) ◽

pp. 766-775 ◽

Cited By ~ 10

Author(s):

Li Fu ◽

Chunyuan Zhu ◽

Xiaomeng Ding ◽

Xiaoyan Yang ◽

Paul F. Morris ◽

...

Keyword(s):

Cell Death ◽

Fungal Pathogens ◽

Phytophthora Capsici ◽

Critical Role ◽

Pectate Lyase ◽

Pectate Lyases ◽

Cell Death Response ◽

Wide Range ◽

Pepper Leaves

Pectate lyases (PL) play a critical role in pectin degradation. PL have been extensively studied in major bacterial and fungal pathogens of a wide range of plant species. However, the contribution of PL to infection by oomycete pathogens remains largely unknown. Here, we cloned 22 full-length pectate lyase (PcPL) genes from a highly aggressive strain of Phytophthora capsici SD33. Of these, PVX agroinfiltration revealed that 12 PcPL genes were found to be highly induced during infection of pepper by SD33 but the induction level was twofold less in a mildly aggressive strain, YN07. The four genes with the highest transcript levels as measured by by quantitative reverse-transcription polymerase chain reaction (PcPL1, PcPL15, PcPL16, and PcPL20) also produced a severe cell death response following transient expression in pepper leaves but the other eight PcPL genes did not. Overexpression of these four genes increased the virulence of SD33 on pepper slightly, and increased it more substantially during infection of tobacco. Overexpression of the genes in YN07 restored its aggressiveness to near that of SD33. Gene silencing experiments with the 12 PcPL genes produced diverse patterns of silencing of PcPL genes, from which it could be inferred from regression analysis that PcPL1, PcPL16, and PcPL20 could account for nearly all of the contributions of the PcPL genes to virulence.

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Faculty Opinions recommendation of Loss of cyclophilin D reveals a critical role for mitochondrial permeability transition in cell death.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1025130.301711 ◽

2005 ◽

Author(s):

Atan Gross

Keyword(s):

Cell Death ◽

Mitochondrial Permeability Transition ◽

Critical Role ◽

Permeability Transition ◽

Cyclophilin D ◽

Mitochondrial Permeability

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Faculty Opinions recommendation of Loss of cyclophilin D reveals a critical role for mitochondrial permeability transition in cell death.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1025130.297852 ◽

2005 ◽

Author(s):

Robert Sapolsky

Keyword(s):

Cell Death ◽

Mitochondrial Permeability Transition ◽

Critical Role ◽

Permeability Transition ◽

Cyclophilin D ◽

Mitochondrial Permeability

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Reverse Screening Bioinformatics Approach to Identify Potential Anti Breast Cancer Targets Using Thymoquinone from Neutraceuticals Black Cumin Oil

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520619666190124155359 ◽

2019 ◽

Vol 19 (5) ◽

pp. 599-609 ◽

Cited By ~ 1

Author(s):

Sumathi Sundaravadivelu ◽

Sonia K. Raj ◽

Banupriya S. Kumar ◽

Poornima Arumugamand ◽

Padma P. Ragunathan

Keyword(s):

Breast Cancer ◽

Gene Expression ◽

Cell Cycle ◽

Cell Death ◽

In Silico ◽

Chemotherapeutic Agents ◽

Normal Cells ◽

Black Cumin ◽

In Silico Docking ◽

Wide Range

Background: Functional foods, neutraceuticals and natural antioxidants have established their potential roles in the protection of human health and diseases. Thymoquinone (TQ), the main bioactive component of Nigella sativa seeds (black cumin seeds), a plant derived neutraceutical was used by ancient Egyptians because of their ability to cure a variety of health conditions and used as a dietary food supplement. Owing to its multi targeting nature, TQ interferes with a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Additionally, TQ can specifically sensitize tumor cells towards conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy) and simultaneously minimize therapy-associated toxic effects in normal cells besides being cost effective and safe. TQ was found to play a protective role when given along with chemotherapeutic agents to normal cells. Methods: In the present study, reverse in silico docking approach was used to search for potential molecular targets for cancer therapy. Various metastatic and apoptotic targets were docked with the target ligand. TQ was also tested for its anticancer activities for its ability to cause cell death, arrest cell cycle and ability to inhibit PARP gene expression. Results: In silico docking studies showed that TQ effectively docked metastatic targets MMPs and other apoptotic and cell proliferation targets EGFR. They were able to bring about cell death mediated by apoptosis, cell cycle arrest in the late apoptotic stage and induce DNA damage too. TQ effectively down regulated PARP gene expression which can lead to enhanced cancer cell death. Conclusion: Thymoquinone a neutraceutical can be employed as a new therapeutic agent to target triple negative breast cancer which is otherwise difficult to treat as there are no receptors on them. Can be employed along with standard chemotherapeutic drugs to treat breast cancer as a combinatorial therapy.

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Shooting a Tiger

10.1093/oso/9780199489381.001.0001 ◽

2018 ◽

Author(s):

Vijaya Ramadas Mandala

Keyword(s):

Critical Role ◽

Late Nineteenth Century ◽

Way Of Life ◽

Colonial India ◽

British Raj ◽

Early Colonial ◽

Wide Range ◽

Forest Legislation ◽

Imperial Governance ◽

North And South

The main contention of Shooting a Tiger is that hunting during the colonial period was not merely a recreational activity, but a practice intimately connected with imperial governance. The book positions shikar or hunting at the heart of colonial rule by demonstrating that, for the British in India, it served as a political, practical, and symbolic apparatus in the consolidation of power and rule during the nineteenth and early twentieth centuries. The book analyses early colonial hunting during the Company period, and then surveys different aspects of hunting during the high imperial decades in the later nineteenth and early twentieth centuries. The book draws upon an impressive array of archival material and uses a wide range of evidence to support its contentions. It examines hunting at a variety of social and ethnic levels—military, administrative, elite, princely India, Indian professional hunters, and in terms of Indian auxiliaries and (sometimes) resisters. It also deals with different geographical contexts—the plains, the mountains, north and south India. The exclusive privilege of hunting exercised by the ruling classes, following colonial forest legislation, continued to be extended to the Indian princes who played a critical role in sustaining the lavish hunts that became the hallmark of the late nineteenth-century British Raj. Hunting was also a way of life in colonial India, undertaken by officials and soldiers alike alongside their everyday duties, necessary for their mental sustenance and vital for the smooth operation of the colonial administration. There are also two final chapters on conservation, particularly the last chapter focusing on two British hunter-turned-conservationists, Jim Corbett and Colonel Richard Burton.

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Individual Expression of Hepatitis A Virus 3C Protease Induces Ferroptosis in Human Cells In Vitro

International Journal of Molecular Sciences ◽

10.3390/ijms22157906 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7906

Author(s):

Alexey A. Komissarov ◽

Maria A. Karaseva ◽

Marina P. Roschina ◽

Andrey V. Shubin ◽

Nataliya A. Lunina ◽

...

Keyword(s):

Cell Death ◽

Hepatitis A ◽

Hepatitis A Virus ◽

Proteolytic Enzymes ◽

Morphological Changes ◽

Human Cells ◽

Mitochondrial Potential ◽

3C Protease ◽

Wide Range

Regulated cell death (RCD) is a fundamental process common to nearly all living beings and essential for the development and tissue homeostasis in animals and humans. A wide range of molecules can induce RCD, including a number of viral proteolytic enzymes. To date, numerous data indicate that picornaviral 3C proteases can induce RCD. In most reported cases, these proteases induce classical caspase-dependent apoptosis. In contrast, the human hepatitis A virus 3C protease (3Cpro) has recently been shown to cause caspase-independent cell death accompanied by previously undescribed features. Here, we expressed 3Cpro in HEK293, HeLa, and A549 human cell lines to characterize 3Cpro-induced cell death morphologically and biochemically using flow cytometry and fluorescence microscopy. We found that dead cells demonstrated necrosis-like morphological changes including permeabilization of the plasma membrane, loss of mitochondrial potential, as well as mitochondria and nuclei swelling. Additionally, we showed that 3Cpro-induced cell death was efficiently blocked by ferroptosis inhibitors and was accompanied by intense lipid peroxidation. Taken together, these results indicate that 3Cpro induces ferroptosis upon its individual expression in human cells. This is the first demonstration that a proteolytic enzyme can induce ferroptosis, the recently discovered and actively studied type of RCD.

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Autophagy Deficiency by Atg4B Loss Leads to Metabolomic Alterations in Mice

Metabolites ◽

10.3390/metabo11080481 ◽

2021 ◽

Vol 11 (8) ◽

pp. 481

Author(s):

Gemma G. Martínez-García ◽

Raúl F. Pérez ◽

Álvaro F. Fernández ◽

Sylvere Durand ◽

Guido Kroemer ◽

...

Keyword(s):

Skeletal Muscle ◽

Amino Acids ◽

Mammalian Cells ◽

Tissue Homeostasis ◽

In Vivo Studies ◽

Protective Mechanism ◽

Cardiac Damage ◽

Wide Range ◽

First Time

Autophagy is an essential protective mechanism that allows mammalian cells to cope with a variety of stressors and contributes to maintaining cellular and tissue homeostasis. Due to these crucial roles and also to the fact that autophagy malfunction has been described in a wide range of pathologies, an increasing number of in vivo studies involving animal models targeting autophagy genes have been developed. In mammals, total autophagy inactivation is lethal, and constitutive knockout models lacking effectors of this route are not viable, which has hindered so far the analysis of the consequences of a systemic autophagy decline. Here, we take advantage of atg4b−/− mice, an autophagy-deficient model with only partial disruption of the process, to assess the effects of systemic reduction of autophagy on the metabolome. We describe for the first time the metabolic footprint of systemic autophagy decline, showing that impaired autophagy results in highly tissue-dependent alterations that are more accentuated in the skeletal muscle and plasma. These changes, which include changes in the levels of amino-acids, lipids, or nucleosides, sometimes resemble those that are frequently described in conditions like aging, obesity, or cardiac damage. We also discuss different hypotheses on how impaired autophagy may affect the metabolism of several tissues in mammals.

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Protective Effect of Osmundacetone against Neurological Cell Death Caused by Oxidative Glutamate Toxicity

Biomolecules ◽

10.3390/biom11020328 ◽

2021 ◽

Vol 11 (2) ◽

pp. 328

Author(s):

Tuy An Trinh ◽

Young Hye Seo ◽

Sungyoul Choi ◽

Jun Lee ◽

Ki Sung Kang

Keyword(s):

Oxidative Stress ◽

Cell Death ◽

Defense Mechanism ◽

Neuroprotective Effect ◽

Glutamate Release ◽

Chromatin Condensation ◽

Critical Role ◽

Glutamate Toxicity ◽

Heme Oxygenase 1 ◽

Brain Functions

Oxidative stress is one of the main causes of brain cell death in neurological disorders. The use of natural antioxidants to maintain redox homeostasis contributes to alleviating neurodegeneration. Glutamate is an excitatory neurotransmitter that plays a critical role in many brain functions. However, excessive glutamate release induces excitotoxicity and oxidative stress, leading to programmed cell death. Our study aimed to evaluate the effect of osmundacetone (OAC), isolated from Elsholtzia ciliata (Thunb.) Hylander, against glutamate-induced oxidative toxicity in HT22 hippocampal cells. The effect of OAC treatment on excess reactive oxygen species (ROS), intracellular calcium levels, chromatin condensation, apoptosis, and the expression level of oxidative stress-related proteins was evaluated. OAC showed a neuroprotective effect against glutamate toxicity at a concentration of 2 μM. By diminishing the accumulation of ROS, as well as stimulating the expression of heat shock protein 70 (HSP70) and heme oxygenase-1 (HO-1), OAC triggered the self-defense mechanism in neuronal cells. The anti-apoptotic effect of OAC was demonstrated through its inhibition of chromatin condensation, calcium accumulation, and reduction of apoptotic cells. OAC significantly suppressed the phosphorylation of mitogen-activated protein kinases (MAPKs), including c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38 kinases. Thus, OAC could be a potential agent for supportive treatment of neurodegenerative diseases.

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