scholarly journals Entomophthovirus: An insect-derived iflavirus that infects a behavior manipulating fungal pathogen of dipterans

2018 ◽  
Author(s):  
Maxwell C. Coyle ◽  
Carolyn N. Elya ◽  
Michael Bronski ◽  
Michael B. Eisen
Keyword(s):  
Fungal Pathogen ◽  
Rna Virus ◽  
Delia Radicum ◽  
Sequencing Data ◽  
Entomophthora Muscae ◽  
Positive Strand Rna Virus ◽  
Close Relatives ◽  
Positive Strand Rna

AbstractWe discovered a virus infecting Entomophthora muscae, a behavior-manipulating fungal pathogen of dipterans. The virus, which we name Entomophthovirus, is a capsid-forming, positive-strand RNA virus in the viral family iflaviridae, whose known members almost exclusively infect insects. We show that the virus RNA is expressed at high levels in fungal cells in vitro and during in vivo infections of Drosophila melanogaster, and that virus particles are present in E. muscae. Two close relatives of the virus had been previously described as insect viruses based on the presence of viral genomes in transcriptomes assembled from RNA extracted from wild dipterans. By analyzing sequencing data from these earlier reports, we show that both dipteran samples were co-infected with E. muscae. We also find the virus in RNA sequencing data from samples of two other species of dipterans, Musca domestica and Delia radicum, known to be infected with E. muscae. These data establish that Entomophthovirus is widely, and seemingly obligately, associated with E. muscae. As other members of the iflaviridae cause behavioral changes in insects, we speculate on the possibility that Entomophthovirus plays a role in E. muscae involved host manipulation.

scholarly journals Interactions between the Structural Domains of the RNA Replication Proteins of Plant-Infecting RNA Viruses

1998 ◽  
Vol 72 (9) ◽  
pp. 7160-7169 ◽  
Author(s):  
Erin K. O’Reilly ◽  
Zhaohui Wang ◽  
Roy French ◽  
C. Cheng Kao
Keyword(s):  
Mosaic Virus ◽  
Rna Viruses ◽  
Rna Virus ◽  
Rna Replication ◽  
Brome Mosaic Virus ◽  
Replication Proteins ◽  
Mutant Proteins ◽  
Positive Strand Rna Virus ◽  
Positive Strand Rna

ABSTRACT Brome mosaic virus (BMV), a positive-strand RNA virus, encodes two replication proteins: the 2a protein, which contains polymerase-like sequences, and the 1a protein, with N-terminal putative capping and C-terminal helicase-like sequences. These two proteins are part of a multisubunit complex which is necessary for viral RNA replication. We have previously shown that the yeast two-hybrid assay consistently duplicated results obtained from in vivo RNA replication assays and biochemical assays of protein-protein interaction, thus permitting the identification of additional interacting domains. We now map an interaction found to take place between two 1a proteins. Using previously characterized 1a mutants, a perfect correlation was found between the in vivo phenotypes of these mutants and their abilities to interact with wild-type 1a (wt1a) and each other. Western blot analysis revealed that the stabilities of many of the noninteracting mutant proteins were similar to that of wt1a. Deletion analysis of 1a revealed that the N-terminal 515 residues of the 1a protein are required and sufficient for 1a-1a interaction. This intermolecular interaction between the putative capping domain and itself was detected in another tripartite RNA virus, cucumber mosaic virus (CMV), suggesting that the 1a-1a interaction is a feature necessary for the replication of tripartite RNA viruses. The boundaries for various activities are placed in the context of the predicted secondary structures of several 1a-like proteins of members of the alphavirus-like superfamily. Additionally, we found a novel interaction between the putative capping and helicase-like portions of the BMV and CMV 1a proteins. Our cumulative data suggest a working model for the assembly of the BMV RNA replicase.

scholarly journals Transfection of Diaporthe perjuncta with Diaporthe RNA Virus

2003 ◽  
Vol 69 (7) ◽  
pp. 3952-3956 ◽  
Author(s):  
Ntsane Moleleki ◽  
Schalk W. van Heerden ◽  
Michael J. Wingfield ◽  
Brenda D. Wingfield ◽  
Oliver Preisig
Keyword(s):  
South African ◽  
Rna Virus ◽  
Cryphonectria Parasitica ◽  
Pathogenicity Test ◽  
New Host ◽  
Rna Transcripts ◽  
Reverse Transcription Pcr ◽  
Positive Strand Rna Virus ◽  
Positive Strand Rna

ABSTRACT Diaporthe perjuncta is a pathogen of grapevines worldwide. A positive-strand RNA virus, Diaporthe RNA virus (DaRV), occurs in hypovirulent isolates of this fungus. A virus-free isolate from a South African grapevine was transfected with in vitro-transcribed positive strands of DaRV. Based on reverse transcription-PCR and partial sequence analysis, the transfected virus was identified as DaRV. The in vitro-transcribed RNA transcripts used to transfect fungal spheroplasts contained parts of the vector at their distal ends. These vector sequences were separated from the DaRV genome during replication in the new host. The transfected isolate had morphological features that differed from those of the isogenic virus-free strain, including production of a yellow pigment, a decreased growth rate, and lack of sporulation. An apple-based pathogenicity test did not reveal any differences in virulence between the virus-free and DaRV-transfected isolates. This study showed that virus-free fungal hosts can be successfully transfected with viruses other than the Cryphonectria parasitica hypovirus.

scholarly journals A Primary Determinant of Cap-Independent Translation Is Located in the 3′-Proximal Region of the Tomato Bushy Stunt Virus Genome

1999 ◽  
Vol 73 (11) ◽  
pp. 8982-8988 ◽  
Author(s):  
Baodong Wu ◽  
K. Andrew White
Keyword(s):  
Rna Virus ◽  
Present Report ◽  
Tomato Bushy Stunt Virus ◽  
Translational Efficiency ◽  
Genome Replication ◽  
Appreciable Effect ◽  
Positive Strand Rna ◽  
Independent Translation

ABSTRACT Tomato bushy stunt virus (TBSV) is a positive-strand RNA virus and is the prototype member of the genus Tombusvirus. The genomes of members of this genus are not polyadenylated, and prevailing evidence supports the absence of a 5′ cap structure. Previously, a 167-nucleotide-long segment (region 3.5) located near the 3′ terminus of the TBSV genome was implicated as a determinant of translational efficiency (S.K. Oster, B. Wu and K. A. White, J. Virol. 72:5845–5851, 1998). In the present report, we provide evidence that a 3′-proximal segment of the genome, which includes region 3.5, is involved in facilitating cap-independent translation. Our results indicate that (i) a 5′ cap structure can substitute functionally for the absence of region 3.5 in viral and chimeric reporter mRNAs in vivo; (ii) deletion of region 3.5 from viral and chimeric mRNAs has no appreciable effect on message stability; (iii) region 3.5 represents part of a larger 3′ proximal element, designated as the 3′ cap-independent translational enhancer (3′CITE), that is required for proficient cap-independent translation; (iv) the 3′CITE also facilitates cap-dependent translation; (v) none of the major viral proteins are required for 3′CITE activity; and (vi) no significant 3′CITE-dependent stimulation of translation was observed when mRNAs were tested in vitro in wheat germ extract under various assay conditions. This latter property distinguishes the 3′CITE from other characterized plant viral 3′-proximal cap-independent translational enhancers. Additionally, because the 3′CITE overlaps withcis-acting replication signals, it could potentially participate in regulating the initiation of genome replication.

scholarly journals A Brome Mosaic Virus Intergenic RNA3 Replication Signal Functions with Viral Replication Protein 1a To Dramatically Stabilize RNA In Vivo

1999 ◽  
Vol 73 (4) ◽  
pp. 2622-2632 ◽  
Author(s):  
Michael L. Sullivan ◽  
Paul Ahlquist
Keyword(s):  
Mosaic Virus ◽  
Rna Virus ◽  
Rna Polymerase Iii ◽  
Rna Replication ◽  
Brome Mosaic Virus ◽  
Positive Strand ◽  
Signal Functions ◽  
Positive Strand Rna Virus ◽  
Positive Strand Rna

ABSTRACT Brome mosaic virus (BMV), a positive-strand RNA virus in the alphavirus-like superfamily, encodes two RNA replication proteins. The 1a protein has putative helicase and RNA-capping domains, whereas 2a contains a polymerase-like domain. Saccharomyces cerevisiae expressing 1a and 2a is capable of replicating a BMV RNA3 template produced by in vivo transcription of a DNA copy of RNA3. Although insufficient for RNA3 replication, the expression of 1a protein alone results in a dramatic and specific stabilization of the RNA3 template in yeast. As one step toward understanding 1a-induced stabilization of RNA3, the interactions involved, and its possible relation to RNA replication, we have identified thecis-acting sequences required for this effect. We find that 1a-induced stabilization is mediated by a 150- to 190-base segment of the RNA3 intergenic region corresponding to a previously identified enhancer of RNA3 replication. Moreover, this segment is sufficient to confer 1a-induced stability on a heterologous β-globin RNA. Within this intergenic segment, partial deletions that inhibited 1a-induced stabilization in yeast expressing 1a alone resulted in parallel decreases in the levels of negative- and positive-strand RNA3 replication products in yeast expressing 1a and 2a. In particular, a small deletion encompassing a motif corresponding to the box B element of RNA polymerase III promoters dramatically reduced the ability of RNAs to respond to 1a or 1a and 2a. These and other findings suggest that 1a-induced stabilization likely reflects an early template selection step in BMV RNA replication.

scholarly journals GCH1 induces immunosuppression through metabolic reprogramming and IDO1 upregulation in triple-negative breast cancer

2021 ◽  
Vol 9 (7) ◽  
pp. e002383
Author(s):  
Jin-Li Wei ◽  
Si-Yu Wu ◽  
Yun-Song Yang ◽  
Yi Xiao ◽  
Xi Jin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Molecular Taxonomy ◽  
Underlying Mechanism ◽  
Metabolic Reprogramming ◽  
Sequencing Data ◽  
Aryl Hydrocarbon

PurposeRegulatory T cells (Tregs) heavily infiltrate triple-negative breast cancer (TNBC), and their accumulation is affected by the metabolic reprogramming in cancer cells. In the present study, we sought to identify cancer cell-intrinsic metabolic modulators correlating with Tregs infiltration in TNBC.Experimental designUsing the RNA-sequencing data from our institute (n=360) and the Molecular Taxonomy of Breast Cancer International Consortium TNBC cohort (n=320), we calculated the abundance of Tregs in each sample and evaluated the correlation between gene expression levels and Tregs infiltration. Then, in vivo and in vitro experiments were performed to verify the correlation and explore the underlying mechanism.ResultsWe revealed that GTP cyclohydrolase 1 (GCH1) expression was positively correlated with Tregs infiltration and high GCH1 expression was associated with reduced overall survival in TNBC. In vivo and in vitro experiments showed that GCH1 increased Tregs infiltration, decreased apoptosis, and elevated the programmed cell death-1 (PD-1)-positive fraction. Metabolomics analysis indicated that GCH1 overexpression reprogrammed tryptophan metabolism, resulting in L-5-hydroxytryptophan (5-HTP) accumulation in the cytoplasm accompanied by kynurenine accumulation and tryptophan reduction in the supernatant. Subsequently, aryl hydrocarbon receptor, activated by 5-HTP, bound to the promoter of indoleamine 2,3-dioxygenase 1 (IDO1) and thus enhanced the transcription of IDO1. Furthermore, the inhibition of GCH1 by 2,4-diamino-6-hydroxypyrimidine (DAHP) decreased IDO1 expression, attenuated tumor growth, and enhanced the tumor response to PD-1 blockade immunotherapy.ConclusionsTumor-cell-intrinsic GCH1 induced immunosuppression through metabolic reprogramming and IDO1 upregulation in TNBC. Inhibition of GCH1 by DAHP serves as a potential immunometabolic strategy in TNBC.

scholarly journals The effect of dipeptidyl peptidase IV on disease-associated microglia phenotypic transformation in epilepsy

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Zhicheng Zheng ◽  
Peiyu Liang ◽  
Baohua Hou ◽  
Xin Lu ◽  
Qianwen Ma ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Neurological Diseases ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Sequencing Data ◽  
Migration Ability ◽  
Dpp4 Inhibitor ◽  
Phenotypic Transformation

Abstract Background Accumulating evidence suggests that disease-associated microglia (DAM), a recently discovered subset of microglia, plays a protective role in neurological diseases. Targeting DAM phenotypic transformation may provide new therapeutic options. However, the relationship between DAM and epilepsy remains unknown. Methods Analysis of public RNA-sequencing data revealed predisposing factors (such as dipeptidyl peptidase IV; DPP4) for epilepsy related to DAM conversion. Anti-epileptic effect was assessed by electroencephalogram recordings and immunohistochemistry in a kainic acid (KA)-induced mouse model of epilepsy. The phenotype, morphology and function of microglia were assessed by qPCR, western blotting and microscopic imaging. Results Our results demonstrated that DPP4 participated in DAM conversion and epilepsy. The treatment of sitagliptin (a DPP4 inhibitor) attenuated KA-induced epilepsy and promoted the expression of DAM markers (Itgax and Axl) in both mouse epilepsy model in vivo and microglial inflammatory model in vitro. With sitagliptin treatment, microglial cells did not display an inflammatory activation state (enlarged cell bodies). Furthermore, these microglia exhibited complicated intersections, longer processes and wider coverage of parenchyma. In addition, sitagliptin reduced the activation of NF-κB signaling pathway and inhibited the expression of iNOS, IL-1β, IL-6 and the proinflammatory DAM subset gene CD44. Conclusion The present results highlight that the DPP4 inhibitor sitagliptin can attenuate epilepsy and promote DAM phenotypic transformation. These DAM exhibit unique morphological features, greater migration ability and better surveillance capability. The possible underlying mechanism is that sitagliptin can reduce the activation of NF-κB signaling pathway and suppress the inflammatory response mediated by microglia. Thus, we propose DPP4 may act as an attractive direction for DAM research and a potential therapeutic target for epilepsy.

EPCO-18. A MESENCHYMAL CELL POPULATION MEDIATES RESISTANCE TO AURORA KINASE INHIBITORS IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi5-vi5
Author(s):  
Robert Suter ◽  
Vasileios Stathias ◽  
Anna Jermakowicz ◽  
Hari Pradhyumnan ◽  
Maurizio Affer ◽  
...  
Keyword(s):  
Single Cell ◽  
Small Molecule ◽  
Kinase Inhibitor ◽  
Patient Survival ◽  
Aurora Kinase ◽  
Adult Brain ◽  
Sequencing Data ◽  
Kinase Inhibition

Abstract Glioblastoma (GBM) remains the most common adult brain cancer, with a dismal average patient survival of less than two years. No new treatments have been approved for GBM since the introduction of the alkylating agent temozolomide in 2005. Even then, temozolomide treatment only increases the average survival of GBM patients by a few months. Thus, novel therapeutic options are direly needed. The aurora kinases A and B are targetable and overexpressed in GBM, and their expression is highly correlated with patient survival outcomes. Our lab has found that small molecule aurora kinase inhibition reduces GBM tumor growth in vitro and in vivo, however, eventually tumors still grow. Computational analysis integrating compound transcriptional response signatures from the LINCS L1000 dataset with the single-cell RNA-sequencing data of patient GBM tumors resected at the University of Miami predicts that aurora inhibition targets a subset of cells present within any GBM tumor. Results of in vivo single-cell perturbation experiments with the aurora kinase inhibitor alisertib coincide with our predictions and reveal a cellular transcriptional phenotype resistant to aurora kinase inhibition, characterized by a mesenchymal expression program. We find that small molecules that are predicted to target different cell populations from alisertib, including this resistant mesenchymal population, synergize with alisertib to kill GBM cells. As a whole, we have identified the cellular population resistant to aurora kinase inhibition and have developed an analytical framework that identifies synergistic small molecule combinations by identifying compounds that target transcriptionally distinct cellular populations within GBM tumors.

scholarly journals Repression and Derepression of Minus-Strand Synthesis in a Plus-Strand RNA Virus Replicon

2004 ◽  
Vol 78 (14) ◽  
pp. 7619-7633 ◽  
Author(s):  
Guohua Zhang ◽  
Jiuchun Zhang ◽  
Anne E. Simon
Keyword(s):  
Solution Structure ◽  
Rna Virus ◽  
Structural Features ◽  
General Mechanism ◽  
Minus Strand ◽  
Turnip Crinkle Virus ◽  
Structural Elements ◽  
Transcription In Vitro

ABSTRACT Plus-strand viral RNAs contain sequences and structural elements that allow cognate RNA-dependent RNA polymerases (RdRp) to correctly initiate and transcribe asymmetric levels of plus and minus strands during RNA replication. cis-acting sequences involved in minus-strand synthesis, including promoters, enhancers, and, recently, transcriptional repressors (J. Pogany, M. R. Fabian, K. A. White, and P. D. Nagy, EMBO J. 22:5602-5611, 2003), have been identified for many viruses. A second example of a transcriptional repressor has been discovered in satC, a replicon associated with turnip crinkle virus. satC hairpin 5 (H5), located proximal to the core hairpin promoter, contains a large symmetrical internal loop (LSL) with sequence complementary to 3′-terminal bases. Deletion of satC 3′-terminal bases or alteration of the putative interacting bases enhanced transcription in vitro, while compensatory exchanges between the LSL and 3′ end restored near-normal transcription. Solution structure analysis indicated that substantial alteration of the satC H5 region occurs when the three 3′-terminal cytidylates are deleted. These results indicate that H5 functions to suppress synthesis of minus strands by sequestering the 3′ terminus from the RdRp. Alteration of a second sequence strongly repressed transcription in vitro and accumulation in vivo, suggesting that this sequence may function as a derepressor to free the 3′ end from interaction with H5. Hairpins with similar sequence and/or structural features that contain sequence complementary to 3′-terminal bases, as well as sequences that could function as derepressors, are located in similar regions in other carmoviruses, suggesting a general mechanism for controlling minus-strand synthesis in the genus.

scholarly journals RNA-Protein Interaction Analysis of SARS-CoV-2 5′ and 3′ Untranslated Regions Reveals a Role of Lysosome-Associated Membrane Protein-2a during Viral Infection

mSystems ◽  
2021 ◽  
Author(s):  
Rohit Verma ◽  
Sandhini Saha ◽  
Shiv Kumar ◽  
Shailendra Mani ◽  
Tushar Kanti Maiti ◽  
...  
Keyword(s):  
Interaction Analysis ◽  
Rna Virus ◽  
Untranslated Regions ◽  
Host Proteins ◽  
Positive Strand ◽  
Replication Complex ◽  
Positive Strand Rna Virus ◽  
Positive Strand Rna ◽  
Viral Genomic Rna

Replication of a positive-strand RNA virus involves an RNA-protein complex consisting of viral genomic RNA, host RNA(s), virus-encoded proteins, and host proteins. Dissecting out individual components of the replication complex will help decode the mechanism of viral replication. 5′ and 3′ UTRs in positive-strand RNA viruses play essential regulatory roles in virus replication.

scholarly journals SARS-CoV-2 Isolation and Propagation from Turkish COVID-19 patients

2020 ◽  
Author(s):  
Cihan Tastan ◽  
Bulut Yurtsever ◽  
Gozde Sir ◽  
Derya Dilek Kancagi ◽  
Sevda Demir ◽  
...  
Keyword(s):  
Rna Virus ◽  
The Novel ◽  
Isolation And Characterization ◽  
Characterization Studies ◽  
Positive Strand Rna Virus ◽  
The Republic ◽  
Novel Coronavirus ◽  
Positive Strand Rna ◽  
Vaccine Testing ◽  
Republic Of Turkey

AbstractThe novel coronavirus pneumonia, which was named later as Coronavirus Disease 2019 (COVID-19), is caused by the Severe Acute Respiratory Syndrome Coronavirus 2, namely SARS-CoV-2. It is a positive-strand RNA virus that is the seventh coronavirus known to infect humans. The COVID-19 outbreak presents enormous challenges for global health behind the pandemic outbreak. The first diagnosed patient in Turkey has been reported by the Republic of Turkey Ministry of Health on March 11, 2020. Today, over ninety thousand cases in Turkey, and two million cases around the world have been declared. Due to the urgent need for vaccine and anti-viral drug, isolation of the virus is crucial. Here, we report one of the first isolation and characterization studies of SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens of diagnosed patients in Turkey. This study provides an isolation and replication methodology, and cell culture tropism of the virus that will be available to the research communities.Article SummaryScientists have isolated virus from Turkish COVID-19 patients. The isolation, propagation, and plaque and immune response assays of the virus described here will serve in following drug discovery and vaccine testing.

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