scholarly journals Susceptibility Genes to Plant Viruses

Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 484 ◽  
Author(s):  
Hernan Garcia-Ruiz
Keyword(s):  
Virus Replication ◽  
Defense Responses ◽  
Plant Viruses ◽  
Host Factors ◽  
Replication Proteins ◽  
Replication Complex ◽  
Virion Assembly ◽  
Rna Translation ◽  
Cellular Factors ◽  
Genetically Determined

Plant viruses use cellular factors and resources to replicate and move. Plants respond to viral infection by several mechanisms, including innate immunity, autophagy, and gene silencing, that viruses must evade or suppress. Thus, the establishment of infection is genetically determined by the availability of host factors necessary for virus replication and movement and by the balance between plant defense and viral suppression of defense responses. Host factors may have antiviral or proviral activities. Proviral factors condition susceptibility to viruses by participating in processes essential to the virus. Here, we review current advances in the identification and characterization of host factors that condition susceptibility to plant viruses. Host factors with proviral activity have been identified for all parts of the virus infection cycle: viral RNA translation, viral replication complex formation, accumulation or activity of virus replication proteins, virus movement, and virion assembly. These factors could be targets of gene editing to engineer resistance to plant viruses.

scholarly journals Multiple Host Factors Interact with the Hypervariable Domain of Chikungunya Virus nsP3 and Determine Viral Replication in Cell-Specific Mode

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Chetan D. Meshram ◽  
Peter Agback ◽  
Nikita Shiliaev ◽  
Nadya Urakova ◽  
James A. Mobley ◽  
...  
Keyword(s):  
Viral Replication ◽  
Virus Replication ◽  
Binding Sites ◽  
Chikungunya Virus ◽  
Host Factors ◽  
Cellular Proteins ◽  
Intrinsically Disordered ◽  
Cell Specificity ◽  
Mosquito Cells ◽  
Cellular Factors

ABSTRACTAlphaviruses are widely distributed in both hemispheres and circulate between mosquitoes and amplifying vertebrate hosts. Geographically separated alphaviruses have adapted to replication in particular organisms. The accumulating data suggest that this adaptation is determined not only by changes in their glycoproteins but also by the amino acid sequence of the hypervariable domain (HVD) of the alphavirus nsP3 protein. We performed a detailed investigation of chikungunya virus (CHIKV) nsP3 HVD interactions with host factors and their roles in viral replication in vertebrate and mosquito cells. The results demonstrate that CHIKV HVD is intrinsically disordered and binds several distinctive cellular proteins. These host factors include two members of the G3BP family and their mosquito homolog Rin, two members of the NAP1 family, and several SH3 domain-containing proteins. Interaction with G3BP proteins or Rin is an absolute requirement for CHIKV replication, although it is insufficient to solely drive it in either vertebrate or mosquito cells. To achieve a detectable level of virus replication, HVD needs to bind members of at least one more protein family in addition to G3BPs. Interaction with NAP1L1 and NAP1L4 plays a more proviral role in vertebrate cells, while binding of SH3 domain-containing proteins to a proline-rich fragment of HVD is more critical for virus replication in the cells of mosquito origin. Modifications of binding sites in CHIKV HVD allow manipulation of the cell specificity of CHIKV replication. Similar changes may be introduced into HVDs of other alphaviruses to alter their replication in particular cells or tissues.IMPORTANCEAlphaviruses utilize a broad spectrum of cellular factors for efficient formation and function of replication complexes (RCs). Our data demonstrate for the first time that the hypervariable domain (HVD) of chikungunya virus nonstructural protein 3 (nsP3) is intrinsically disordered. It binds at least 3 families of cellular proteins, which play an indispensable role in viral RNA replication. The proteins of each family demonstrate functional redundancy. We provide a detailed map of the binding sites on CHIKV nsP3 HVD and show that mutations in these sites or the replacement of CHIKV HVD by heterologous HVD change cell specificity of viral replication. Such manipulations with alphavirus HVDs open an opportunity for development of new irreversibly attenuated vaccine candidates. To date, the disordered protein fragments have been identified in the nonstructural proteins of many other viruses. They may also interact with a variety of cellular factors that determine critical aspects of virus-host interactions.

scholarly journals Reconstitution of an RNA Virus Replicase in Artificial Giant Unilamellar Vesicles Supports Full Replication and Provides Protection for the Double-Stranded RNA Replication Intermediate

2020 ◽  
Vol 94 (18) ◽  
Author(s):  
Nikolay Kovalev ◽  
Judit Pogany ◽  
Peter D. Nagy
Keyword(s):  
Virus Replication ◽  
Rna Synthesis ◽  
Rna Viruses ◽  
Host Factors ◽  
Replication Process ◽  
Double Stranded Rna ◽  
Replication Intermediate ◽  
Cellular Factors ◽  
Positive Strand Rna

ABSTRACT Positive-strand RNA [(+)RNA] viruses are important pathogens of humans, animals, and plants and replicate inside host cells by coopting numerous host factors and subcellular membranes. To gain insights into the assembly of viral replicase complexes (VRCs) and dissect the roles of various lipids and coopted host factors, we have reconstituted Tomato bushy stunt virus (TBSV) replicase using artificial giant unilamellar vesicles (GUVs). We demonstrate that reconstitution of VRCs on GUVs with endoplasmic reticulum (ER)-like phospholipid composition results in a complete cycle of replication and asymmetrical RNA synthesis, which is a hallmark of (+)RNA viruses. TBSV VRCs assembled on GUVs provide significant protection of the double-stranded RNA (dsRNA) replication intermediate against the dsRNA-specific RNase III. The lipid compositions of GUVs have pronounced effects on in vitro TBSV replication, including (−) and (+)RNA synthesis. The GUV-based assay has led to the discovery of the critical role of phosphatidylserine in TBSV replication and a novel role for phosphatidylethanolamine in asymmetrical (+)RNA synthesis. The GUV-based assay also showed stimulatory effects by phosphatidylinositol-3-phosphate [PI(3)P] and ergosterol on TBSV replication. We demonstrate that eEF1A and Hsp70 coopted replicase assembly factors, Vps34 phosphatidylinositol 3-kinase (PI3K) and the membrane-bending ESCRT factors, are required for reconstitution of the active TBSV VRCs in GUVs, further supporting that the novel GUV-based in vitro approach recapitulates critical steps and involves essential coopted cellular factors of the TBSV replication process. Taken together, this novel GUV assay will be highly suitable to dissect the functions of viral and cellular factors in TBSV replication. IMPORTANCE Understanding the mechanism of replication of positive-strand RNA viruses, which are major pathogens of plants, animals, and humans, can lead to new targets for antiviral interventions. These viruses subvert intracellular membranes for virus replication and coopt numerous host proteins, whose functions during virus replication are not yet completely defined. To dissect the roles of various host factors in Tomato bushy stunt virus (TBSV) replication, we have developed an artificial giant unilamellar vesicle (GUV)-based replication assay. The GUV-based in vitro approach recapitulates critical steps of the TBSV replication process. GUV-based reconstitution of the TBSV replicase revealed the need for a complex mixture of phospholipids, especially phosphatidylserine and phosphatidylethanolamine, in TBSV replication. The GUV-based approach will be useful to dissect the functions of essential coopted cellular factors.

scholarly journals Membrane-Associated Flavivirus Replication Complex—Its Organization and Regulation

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1060
Author(s):  
Eiji Morita ◽  
Youichi Suzuki
Keyword(s):  
Protein Translation ◽  
Immune Defense ◽  
Membranous Structure ◽  
Replication Complex ◽  
Virion Assembly ◽  
Cellular Factors ◽  
Life Threatening ◽  
And Function ◽  
Cellular Immune ◽  
Flavivirus Infection

Flavivirus consists of a large number of arthropod-borne viruses, many of which cause life-threatening diseases in humans. A characteristic feature of flavivirus infection is to induce the rearrangement of intracellular membrane structure in the cytoplasm. This unique membranous structure called replication organelle is considered as a microenvironment that provides factors required for the activity of the flaviviral replication complex. The replication organelle serves as a place to coordinate viral RNA amplification, protein translation, and virion assembly and also to protect the viral replication complex from the cellular immune defense system. In this review, we summarize the current understanding of how the formation and function of membrane-associated flaviviral replication organelle are regulated by cellular factors.

scholarly journals Dynamin-Like Proteins of Endocytosis in Plants Are Coopted by Potyviruses To Enhance Virus Infection

2018 ◽  
Vol 92 (23) ◽  
Author(s):  
Guanwei Wu ◽  
Xiaoyan Cui ◽  
Hui Chen ◽  
Justin B. Renaud ◽  
Kangfu Yu ◽  
...  
Keyword(s):  
Virus Infection ◽  
Mosaic Virus ◽  
Virus Replication ◽  
Specific Inhibitor ◽  
Viral Proteins ◽  
Plant Viruses ◽  
Host Factors ◽  
Content Type ◽  
Novel Host ◽  
Intercellular Movement

ABSTRACT Endocytosis and endosomal trafficking regulate the proteins targeted to the plasma membrane and play essential roles in diverse cellular processes, including responses to pathogen attack. Here, we report the identification of Glycine max (soybean) endocytosis dynamin-like protein 5A (GmSDL5A) associated with purified soybean mosaic virus (SMV) virions from soybean using a bottom-up proteomics approach. Knockdown of GmSDL5A and its homologous gene GmSDL12A inhibits SMV infection in soybean. The role of analogous dynamin-like proteins in potyvirus infection was further confirmed and investigated using the Arabidopsis/turnip mosaic virus (TuMV) pathosystem. We demonstrate that dynamin-related proteins 2A and 2B in Arabidopsis thaliana (AtDRP2A, AtDRP2B), homologs of GmSDL5A, are recruited to the virus replication complex (VRC) of TuMV. TuMV infection is inhibited in both A. thaliana drp2a (atdrp2a) and atdrp2b knockout mutants. Overexpression of AtDRP2 promotes TuMV replication and intercellular movement. AtRDP2 interacts with TuMV VPg, CP, CI, and 6K2. Of these viral proteins, VPg, CP, and CI are essential for viral intercellular movement, and 6K2, VPg, and CI are critical components of the VRC. We reveal that VPg and CI are present in the punctate structures labeled by the endocytic tracer FM4-64, suggesting that VPg and CI can be endocytosed. Treatment of plant leaves with a dynamin-specific inhibitor disrupts the delivery of VPg and CI to endocytic structures and suppresses TuMV replication and intercellular movement. Taken together, these data suggest that dynamin-like proteins are novel host factors of potyviruses and that endocytic processes are involved in potyvirus infection. IMPORTANCE It is well known that animal viruses enter host cells via endocytosis, whereas plant viruses require physical assistance, such as human and insect activities, to penetrate the host cell to establish their infection. In this study, we report that the endocytosis pathway is also involved in virus infection in plants. We show that plant potyviruses recruit endocytosis dynamin-like proteins to support their infection. Depletion of them by knockout of the corresponding genes suppresses virus replication, whereas overexpression of them enhances virus replication and intercellular movement. We also demonstrate that the dynamin-like proteins interact with several viral proteins that are essential for virus replication and cell-to-cell movement. We further show that treatment of a dynamin-specific inhibitor disrupts endocytosis and inhibits virus replication and intercellular movement. Therefore, the dynamin-like proteins are novel host factors of potyviruses. The corresponding genes may be manipulated using advanced biotechnology to control potyviral diseases.

scholarly journals Towards plant resistance to viruses using protein-only RNase P

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anthony Gobert ◽  
Yifat Quan ◽  
Mathilde Arrivé ◽  
Florent Waltz ◽  
Nathalie Da Silva ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Virus Replication ◽  
Yield Loss ◽  
Rnase P ◽  
Plant Viruses ◽  
Yellow Mosaic Virus ◽  
Resistance To Viruses ◽  
Target Plant

AbstractPlant viruses cause massive crop yield loss worldwide. Most plant viruses are RNA viruses, many of which contain a functional tRNA-like structure. RNase P has the enzymatic activity to catalyze the 5′ maturation of precursor tRNAs. It is also able to cleave tRNA-like structures. However, RNase P enzymes only accumulate in the nucleus, mitochondria, and chloroplasts rather than cytosol where virus replication takes place. Here, we report a biotechnology strategy based on the re-localization of plant protein-only RNase P to the cytosol (CytoRP) to target plant viruses tRNA-like structures and thus hamper virus replication. We demonstrate the cytosol localization of protein-only RNase P in Arabidopsis protoplasts. In addition, we provide in vitro evidences for CytoRP to cleave turnip yellow mosaic virus and oilseed rape mosaic virus. However, we observe varied in vivo results. The possible reasons have been discussed. Overall, the results provided here show the potential of using CytoRP for combating some plant viral diseases.

The Leucine-Rich Repeat Domain Can Determine Effective Interaction Between RPS2 and Other Host Factors in Arabidopsis RPS2-Mediated Disease Resistance

Genetics ◽  
2001 ◽  
Vol 158 (1) ◽  
pp. 439-450 ◽  
Author(s):  
Diya Banerjee ◽  
Xiaochun Zhang ◽  
Andrew F Bent
Keyword(s):  
Disease Resistance ◽  
Pseudomonas Syringae ◽  
Plant Disease Resistance ◽  
Effective Interaction ◽  
Molecular Genetic ◽  
Defense Responses ◽  
Host Factors ◽  
Leucine Rich Repeat ◽  
Domain Swap ◽  
Allele Specific

Abstract Like many other plant disease resistance genes, Arabidopsis thaliana RPS2 encodes a product with nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains. This study explored the hypothesized interaction of RPS2 with other host factors that may be required for perception of Pseudomonas syringae pathogens that express avrRpt2 and/or for the subsequent induction of plant defense responses. Crosses between Arabidopsis ecotypes Col-0 (resistant) and Po-1 (susceptible) revealed segregation of more than one gene that controls resistance to P. syringae that express avrRpt2. Many F2 and F3 progeny exhibited intermediate resistance phenotypes. In addition to RPS2, at least one additional genetic interval associated with this defense response was identified and mapped using quantitative genetic methods. Further genetic and molecular genetic complementation experiments with cloned RPS2 alleles revealed that the Po-1 allele of RPS2 can function in a Col-0 genetic background, but not in a Po-1 background. The other resistance-determining genes of Po-1 can function, however, as they successfully conferred resistance in combination with the Col-0 allele of RPS2. Domain-swap experiments revealed that in RPS2, a polymorphism at six amino acids in the LRR region is responsible for this allele-specific ability to function with other host factors.

scholarly journals Cell Death Triggered by a Putative Amphipathic Helix of Radish mosaic virus Helicase Protein Is Tightly Correlated With Host Membrane Modification

2015 ◽  
Vol 28 (6) ◽  
pp. 675-688 ◽  
Author(s):  
Masayoshi Hashimoto ◽  
Ken Komatsu ◽  
Ryo Iwai ◽  
Takuya Keima ◽  
Kensaku Maejima ◽  
...  
Keyword(s):  
Cell Death ◽  
Mosaic Virus ◽  
Defense Responses ◽  
Plant Viruses ◽  
Amphipathic Helix ◽  
Membrane Structures ◽  
Membrane Modification ◽  
Systemic Necrosis ◽  
Amino Terminal ◽  
Er Membrane

Systemic necrosis is one of the most severe symptoms caused by plant RNA viruses. Recently, systemic necrosis has been suggested to have similar features to a defense response referred to as the hypersensitive response (HR), a form of programmed cell death. In virus-infected plant cells, host intracellular membrane structures are changed dramatically for more efficient viral replication. However, little is known about whether this replication-associated membrane modification is the cause of the symptoms. In this study, we identified an amino-terminal amphipathic helix of the helicase encoded by Radish mosaic virus (RaMV) (genus Comovirus) as an elicitor of cell death in RaMV-infected plants. Cell death caused by the amphipathic helix had features similar to HR, such as SGT1-dependence. Mutational analyses and inhibitor assays using cerulenin demonstrated that the amphipathic helix–induced cell death was tightly correlated with dramatic alterations in endoplasmic reticulum (ER) membrane structures. Furthermore, the cell death–inducing activity of the amphipathic helix was conserved in Cowpea mosaic virus (genus Comovirus) and Tobacco ringspot virus (genus Nepovirus), both of which are classified in the family Secoviridae. Together, these results indicate that ER membrane modification associated with viral intracellular replication may be recognized to prime defense responses against plant viruses.

Sign in / Sign up

Export Citation Format

Share Document