1
|
Targeting the Inside of Cells with Biologicals: Toxin Routes in a Therapeutic Context. BioDrugs 2023; 37:181-203. [PMID: 36729328 PMCID: PMC9893211 DOI: 10.1007/s40259-023-00580-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2023] [Indexed: 02/03/2023]
Abstract
Numerous toxins translocate to the cytosol in order to fulfil their function. This demonstrates the existence of routes for proteins from the extracellular space to the cytosol. Understanding these routes is relevant to multiple aspects related to therapeutic applications. These include the development of anti-toxin treatments, the potential use of toxins as shuttles for delivering macromolecular cargo to the cytosol or the use of drugs based on toxins. Compared with other strategies for delivery, such as chemicals as carriers for macromolecular delivery or physical methods like electroporation, toxin routes present paths into the cell that potentially cause less damage and can be specifically targeted. The efficiency of delivery via toxin routes is limited. However, low-delivery efficiencies can be entirely sufficient, if delivered cargoes possess an amplification effect or if very few molecules are sufficient for inducing the desired effects. This is known for example from RNA-based vaccines that have been developed during the coronavirus disease 2019 pandemic as well as for other approved RNA-based drugs, which elicited the desired effect despite their typically low delivery efficiencies. The different mechanisms by which toxins enter cells may have implications for their technological utility. We review the mechanistic principles of the translocation pathway of toxins from the extracellular space to the cytosol, the delivery efficiencies, and therapeutic strategies or applications that exploit toxin routes for intracellular delivery.
Collapse
|
2
|
Mishra V, Mishra R, Shamra RS. Ribosome inactivating proteins - An unfathomed biomolecule for developing multi-stress tolerant transgenic plants. Int J Biol Macromol 2022; 210:107-122. [PMID: 35525494 DOI: 10.1016/j.ijbiomac.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/10/2022] [Accepted: 05/01/2022] [Indexed: 11/15/2022]
Abstract
Transgenic crops would serve as a tool to overcome the forthcoming crisis in food security and environmental safety posed by degrading land and changing global climate. Commercial transgenic crops developed so far focus on single stress; however, sustaining crop yield to ensure food security requires transgenics tolerant to multiple environmental stresses. Here we argue and demonstrate the untapped potential of ribosome inactivating proteins (RIPs), translation inhibitors, as potential transgenes in developing transgenics to combat multiple stresses in the environment. Plant RIPs target the fundamental processes of the cell with very high specificity to the infecting pests. While controlling pathogens, RIPs also cause ectopic expression of pathogenesis-related proteins and trigger systemic acquired resistance. On the other hand, during abiotic stress, RIPs show antioxidant activity and trigger both enzyme-dependent and enzyme-independent metabolic pathways, alleviating abiotic stress such as drought, salinity, temperature, etc. RIPs express in response to specific environmental signals; therefore, their expression obviates additional physiological load on the transgenic plants instead of the constitutive expression. Based on evidence from its biological significance, ecological roles, laboratory- and controlled-environment success of its transgenics, and ethical merits, we unravel the potential of RIPs in developing transgenic plants showing co-tolerance to multiple environmental stresses.
Collapse
Affiliation(s)
- Vandana Mishra
- Bioresources and Environmental Biotechnology Laboratory, Department of Environmental Studies, University of Delhi, Delhi 110007, India.
| | - Ruchi Mishra
- Bioresources and Environmental Biotechnology Laboratory, Department of Environmental Studies, University of Delhi, Delhi 110007, India; Jesus and Mary College, University of Delhi, Chanakyapuri, Delhi 110021, India.
| | - Radhey Shyam Shamra
- Bioresources and Environmental Biotechnology Laboratory, Department of Environmental Studies, University of Delhi, Delhi 110007, India; Delhi School of Climate Change & Sustainability, Institute of Eminence, University of Delhi, Delhi 110007, India.
| |
Collapse
|
3
|
Scopolia mild mottle virus: a new tobamovirus isolated from a Scopolia japonica plant in Japan. Arch Virol 2022; 167:947-951. [PMID: 35103854 DOI: 10.1007/s00705-022-05371-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/15/2021] [Indexed: 11/02/2022]
Abstract
A tobamovirus was isolated from leaves of a Scopolia japonica plant showing mild yellowing. Back-inoculation of healthy Scopolia japonica with the isolated virus induced mild mottle on upper leaves. Phylogenetic analysis based on coat protein and replicase protein sequences revealed that the newly isolated tobamovirus was most closely related to yellow tailflower mild mottle virus (YTMMV). The newly isolated tobamovirus shared the highest nucleotide sequence identity (71%) with YTMMV, which is lower than the cutoff (90%) set for species demarcation in the genus Tobamovirus. Thus, our result suggested that scopolia mild mottle virus (SMMoV) is a new tobamovirus that infects Scopolia japonica plants in Japan.
Collapse
|
4
|
Citores L, Iglesias R, Ferreras JM. Antiviral Activity of Ribosome-Inactivating Proteins. Toxins (Basel) 2021; 13:80. [PMID: 33499086 PMCID: PMC7912582 DOI: 10.3390/toxins13020080] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.22) that inactivate ribosomes thus inhibiting protein synthesis. The antiviral properties of RIPs have been investigated for more than four decades. However, interest in these proteins is rising due to the emergence of infectious diseases caused by new viruses and the difficulty in treating viral infections. On the other hand, there is a growing need to control crop diseases without resorting to the use of phytosanitary products which are very harmful to the environment and in this respect, RIPs have been shown as a promising tool that can be used to obtain transgenic plants resistant to viruses. The way in which RIPs exert their antiviral effect continues to be the subject of intense research and several mechanisms of action have been proposed. The purpose of this review is to examine the research studies that deal with this matter, placing special emphasis on the most recent findings.
Collapse
Affiliation(s)
| | | | - José M. Ferreras
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain; (L.C.); (R.I.)
| |
Collapse
|
5
|
Guo W, Lu X, Liu B, Yan H, Feng J. Anti-TMV activity and mode of action of three alkaloids isolated from Chelidonium majus. PEST MANAGEMENT SCIENCE 2021; 77:510-517. [PMID: 32815231 DOI: 10.1002/ps.6049] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/05/2020] [Accepted: 08/19/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Plant viral diseases are difficult to control and have caused serious damage to the agricultural industry. Recently, botanical biopesticides characterized by environment friendly, safe to non-target organism and not as susceptible to produce drug resistance, have exhibited great potential to be developed as antiviral agents. To screen the natural products with antiviral effect, three alkaloids possessed anti-tobacco mosaic virus (TMV) activity were isolated from Chelidonium majus and the modes of action were investigated. RESULT The anti-TMV effect of crude extracts at 10 mg mL-1 was 51.73%. Bioassay-guided fractionation and isolation of the compounds with anti-TMV activity were performed on the methanol extract of C. majus yielding three bioactive alkaloids namely: chelerythrine (1), chelidonine (2), and sanguinarine (3). The results of bioassay showed that chelerythrine exhibited great inactivation, proliferation inhibition and protection effects against TMV at 0.5 mg mL-1 with the efficiency of 72.67%, 77.52% and 59.34%, respectively. Chelidonine at 0.1 mg mL-1 can provide 54.90% and 64.45% inhibitions on TMV through inducing resistance in two kinds of tobacco. Sanguinarine showed a weaker protection for resisting TMV in comparison to chelerythrine and chelidonine. CONCLUSION Chelerythrine and chelidonine displayed significant inhibitions on TMV with different modes of action. These results provided important evidence that the extracts in C. majus might be a potential source of new drugs in controlling virus disease agriculturally.
Collapse
Affiliation(s)
- Wenhui Guo
- College of Plant Protection, Engineering and Technology Centers of Biopesticide in Shaanxi, Northwest Agriculture and Forestry University, Yangling, China
| | - Xiang Lu
- College of Plant Protection, Engineering and Technology Centers of Biopesticide in Shaanxi, Northwest Agriculture and Forestry University, Yangling, China
| | - Bin Liu
- College of Plant Protection, Engineering and Technology Centers of Biopesticide in Shaanxi, Northwest Agriculture and Forestry University, Yangling, China
| | - He Yan
- College of Plant Protection, Engineering and Technology Centers of Biopesticide in Shaanxi, Northwest Agriculture and Forestry University, Yangling, China
| | - Juntao Feng
- College of Plant Protection, Engineering and Technology Centers of Biopesticide in Shaanxi, Northwest Agriculture and Forestry University, Yangling, China
| |
Collapse
|
6
|
Choudhary N, Lodha ML, Baranwal VK. The role of enzymatic activities of antiviral proteins from plants for action against plant pathogens. 3 Biotech 2020; 10:505. [PMID: 33184592 PMCID: PMC7642053 DOI: 10.1007/s13205-020-02495-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/19/2020] [Indexed: 11/25/2022] Open
Abstract
Antiviral proteins (AVPs) from plants possess multiple activities, such as N-glycosidase, RNase, DNase enzymatic activity, and induce pathogenesis-related proteins, salicylic acid, superoxide dismutase, peroxidase, and catalase. The N-glycosidase activity releases the adenine residues from sarcin/ricin (S/R) loop of large subunit of ribosomes and interfere the host protein synthesis process and this activity has been attributed for antiviral activity in plant. It has been shown that AVP binds directly to viral genome-linked protein of plant viruses and interfere with protein synthesis of virus. AVPs also possess the RNase and DNase like activity and may be targeting nucleic acid of viruses directly. Recently, the antifungal, antibacterial, and antiinsect properties of AVPs have also been demonstrated. Gene encoding for AVPs has been used for the development of transgenic resistant crops to a broad range of plant pathogens and insect pests. However, the cytotoxicity has been observed in transgenic crops using AVP gene in some cases which can be a limiting factor for its application in agriculture. In this review, we have reviewed various aspects of AVPs particularly their characteristics, possible mode of action and application.
Collapse
Affiliation(s)
- Nandlal Choudhary
- Amity Institute of Virology & Immunology, Amity University Uttar Pradesh, Noida, 201313 India
| | - M. L. Lodha
- Division of Biochemistry, Indian Agricultural Research Institute, Pusa, New Delhi, 110012 India
| | - V. K. Baranwal
- Division of Plant Pathology, Indian Agricultural Research Institute, Pusa, New Delhi, 110012 India
| |
Collapse
|
7
|
Antiviral Activity of PD-L1 and PD-L4, Type 1 Ribosome Inactivating Proteins from Leaves of Phytolacca dioica L. in the Pathosystem Phaseolus vulgaris-Tobacco Necrosis Virus (TNV). Toxins (Basel) 2020; 12:toxins12080524. [PMID: 32824023 PMCID: PMC7472211 DOI: 10.3390/toxins12080524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/07/2020] [Accepted: 08/13/2020] [Indexed: 02/06/2023] Open
Abstract
Using the pathosystem Phaseolus vulgaris-tobacco necrosis virus (TNV), we demonstrated that PD-L1 and PD-L4, type-1 ribosome inactivating proteins (RIPs) from leaves of Phytolacca dioica L., possess a strong antiviral activity. This activity was exerted both when the RIPs and the virus were inoculated together in the same leaf and when they were inoculated or applied separately in the adaxial and abaxial leaf surfaces. This suggests that virus inhibition would mainly occur inside plant cells at the onset of infection. Histochemical studies showed that both PD-L1 and PD-L4 were not able to induce oxidative burst and cell death in treated leaves, which were instead elicited by inoculation of the virus alone. Furthermore, when RIPs and TNV were inoculated together, no sign of H2O2 deposits and cell death were detectable, indicating that the virus could have been inactivated in a very early stage of infection, before the elicitation of a hypersensitivity reaction. In conclusion, the strong antiviral activity is likely exerted inside host cells as soon the virus disassembles to start translation of the viral genome. This activity is likely directed towards both viral and ribosomal RNA, explaining the almost complete abolition of infection when virus and RIP enter together into the cells.
Collapse
|
8
|
The Tug-of-War between Plants and Viruses: Great Progress and Many Remaining Questions. Viruses 2019; 11:v11030203. [PMID: 30823402 PMCID: PMC6466000 DOI: 10.3390/v11030203] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/18/2019] [Accepted: 02/23/2019] [Indexed: 12/19/2022] Open
Abstract
Plants are persistently challenged by various phytopathogens. To protect themselves, plants have evolved multilayered surveillance against all pathogens. For intracellular parasitic viruses, plants have developed innate immunity, RNA silencing, translation repression, ubiquitination-mediated and autophagy-mediated protein degradation, and other dominant resistance gene-mediated defenses. Plant viruses have also acquired diverse strategies to suppress and even exploit host defense machinery to ensure their survival. A better understanding of the defense and counter-defense between plants and viruses will obviously benefit from the development of efficient and broad-spectrum virus resistance for sustainable agriculture. In this review, we summarize the cutting edge of knowledge concerning the defense and counter-defense between plants and viruses, and highlight the unexploited areas that are especially worth investigating in the near future.
Collapse
|
9
|
Lagzian M, Qasemi A, Kaviani P, Mohammadi M. Identification of new promising plant-based lead compounds for inhibition of prokaryotic replicative DNA polymerases: combination of in silico and in vitro studies. J Biomol Struct Dyn 2018; 37:4222-4237. [PMID: 30526389 DOI: 10.1080/07391102.2018.1545701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Emerging widespread bacterial resistance to current antibiotics with traditional targets is one of the major global concerns. Therefore, so many investigations are exploring the potential of other druggable macromolecules of bacteria such as replication machinery components that are not addressed by previous antibiotics. DNA polymerase is the major part of this machine. However, a few studies have been done on it so far. In this respect, we report the discovery of four new plant-based leads against DNA polymerase (pol) IIIC (three leads) and pol IIIE (one lead) of Gram-positive and negative bacteria by combining a sequentially constrained high-throughput virtual screenings on Traditional Chinese Medicine Database with in vitro assays. The compounds displayed relatively good levels of inhibitory effect. They were active against their designated targets at micromolar concentrations. The IC50 values for them are ranged from 25 to 111 μM. In addition, they showed minimum inhibitory concentrations in the range of 8-128 μg/mL against five representatives of pathogenic bacteria species. However, they were inactive against Pseudomonas aeruginosa. Given these results, these leads hold promise for future modification and optimization to be more effective in lower concentrations and also against most of the important bacterial species. Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Milad Lagzian
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan , Zahedan , Iran
| | - Ali Qasemi
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan , Zahedan , Iran
| | - Pegah Kaviani
- Department of Biology, University of Skövde , Skövde , Sweden
| | - Malihe Mohammadi
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan , Zahedan , Iran
| |
Collapse
|
10
|
Zhu F, Zhou YK, Ji ZL, Chen XR. The Plant Ribosome-Inactivating Proteins Play Important Roles in Defense against Pathogens and Insect Pest Attacks. FRONTIERS IN PLANT SCIENCE 2018; 9:146. [PMID: 29479367 PMCID: PMC5811460 DOI: 10.3389/fpls.2018.00146] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/25/2018] [Indexed: 05/20/2023]
Abstract
Ribosome-inactivating proteins (RIPs) are toxic N-glycosidases that depurinate eukaryotic and prokaryotic rRNAs, thereby arresting protein synthesis during translation. RIPs are widely found in various plant species and within different tissues. It is demonstrated in vitro and in transgenic plants that RIPs have been connected to defense by antifungal, antibacterial, antiviral, and insecticidal activities. However, the mechanism of these effects is still not completely clear. There are a number of reviews of RIPs. However, there are no reviews on the biological functions of RIPs in defense against pathogens and insect pests. Therefore, in this report, we focused on the effect of RIPs from plants in defense against pathogens and insect pest attacks. First, we summarize the three different types of RIPs based on their physical properties. RIPs are generally distributed in plants. Then, we discuss the distribution of RIPs that are found in various plant species and in fungi, bacteria, algae, and animals. Various RIPs have shown unique bioactive properties including antibacterial, antifungal, antiviral, and insecticidal activity. Finally, we divided the discussion into the biological roles of RIPs in defense against bacteria, fungi, viruses, and insects. This review is focused on the role of plant RIPs in defense against bacteria, fungi, viruses, and insect attacks. The role of plant RIPs in defense against pathogens and insects is being comprehended currently. Future study utilizing transgenic technology approaches to study the mechanisms of RIPs will undoubtedly generate a better comprehending of the role of plant RIPs in defense against pathogens and insects. Discovering additional crosstalk mechanisms between RIPs and phytohormones or reactive oxygen species (ROS) against pathogen and insect infections will be a significant subject in the field of biotic stress study. These studies are helpful in revealing significance of genetic control that can be beneficial to engineer crops tolerance to biotic stress.
Collapse
|
11
|
Islam W, Adnan M, Tayyab M, Hussain M, Islam SU. Phyto-metabolites; An Impregnable Shield against Plant Viruses. Nat Prod Commun 2018. [DOI: 10.1177/1934578x1801300131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Worldwide, economically important crops are under continuous threat from plant viruses as they reproduce within the host and spread via various biological and non biological means. The problem can be minimized via application of integrated management approaches involving utilization of resistant genotypes and reducing the insect vector population. But such strategies are rarely applied in developing countries and farmers prefer to use chemicals against all type of diseases. But increasing use of pesticides is a leading cause of disaster to our ecosystem so alternative means such as phyto-metabolites should be explored for eco friendly management of plant viruses. So here we have reviewed about different phyto-metabolites that can be effectively and potentially used against various plant virus diseases. We further explained about the various primary and secondary metabolites such as alkaloids, essential oils, flavonoids, polysaccharides and proteins. The review highlights the recent advances in the field of phyto-metabolites utilization against plant viruses and sums up via hoping through prospects that future drugs will be safer for human beings and our ecosystem.
Collapse
Affiliation(s)
- Waqar Islam
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
- Fujian Province Key Laboratory for Plant Viruses, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Muhammad Adnan
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Muhammad Tayyab
- College of Crop Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Mubasher Hussain
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Saif Ul Islam
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
- Fujian Province Key Laboratory for Plant Viruses, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| |
Collapse
|
12
|
Domashevskiy AV, Williams S, Kluge C, Cheng SY. Plant Translation Initiation Complex eIFiso4F Directs Pokeweed Antiviral Protein to Selectively Depurinate Uncapped Tobacco Etch Virus RNA. Biochemistry 2017; 56:5980-5990. [PMID: 29064680 DOI: 10.1021/acs.biochem.7b00598] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Pokeweed antiviral protein (PAP) is a ribosome inactivating protein (RIP) that depurinates the sarcin/ricin loop (SRL) of rRNA, inhibiting protein synthesis. PAP depurinates viral RNA, and in doing so, lowers the infectivity of many plant viruses. The mechanism by which PAP accesses uncapped viral RNA is not known, impeding scientists from developing effective antiviral agents for the prevention of the diseases caused by uncapped RNA viruses. Kinetic rates of PAP interacting with tobacco etch virus (TEV) RNA, in the presence and absence of eIFiso4F, were examined, addressing how the eIF affects selective PAP targeting and depurination of the uncapped viral RNA. PAP-eIFs copurification assay and fluorescence resonance energy transfer demonstrate that PAP forms a ternary complex with the eIFiso4G and eIFiso4E, directing the depurination of uncapped viral RNA. eIFiso4F selectively targets PAP to depurinate TEV RNA by increasing PAP's specificity constant for uncapped viral RNA 12-fold, when compared to the depurination of an oligonucleotide RNA that mimics the SRL of large rRNA, and cellular capped luciferase mRNA. This explains how PAP is able to lower infectivity of pokeweed viruses, while preserving its own ribosomes and cellular RNA from depurination: PAP utilizes cellular eIFiso4F in a novel strategy to target uncapped viral RNA. It may be possible to modulate and utilize these PAP-eIFs interactions for their public health benefit; by repurposing them to selectively target PAP to depurinate uncapped viral RNA, many plant and animal diseases caused by these viruses could be alleviated.
Collapse
Affiliation(s)
- Artem V Domashevskiy
- Department of Sciences, John Jay College of Criminal Justice, the City University of New York , New York, New York 10019, United States
| | - Shawn Williams
- Department of Sciences, John Jay College of Criminal Justice, the City University of New York , New York, New York 10019, United States
| | - Christopher Kluge
- Department of Sciences, John Jay College of Criminal Justice, the City University of New York , New York, New York 10019, United States
| | - Shu-Yuan Cheng
- Department of Sciences, John Jay College of Criminal Justice, the City University of New York , New York, New York 10019, United States
| |
Collapse
|
13
|
Zhao L, Feng C, Wu K, Chen W, Chen Y, Hao X, Wu Y. Advances and prospects in biogenic substances against plant virus: A review. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2017; 135:15-26. [PMID: 28043326 DOI: 10.1016/j.pestbp.2016.07.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 07/13/2016] [Accepted: 07/18/2016] [Indexed: 05/26/2023]
Abstract
Plant virus diseases, known as 'plant cancer', are the second largest plant diseases after plant fungal diseases, which have caused great damage to agricultural industry. Since now, the most direct and effective method for controlling viruses is chemotherapeutics, except for screening of anti-disease species. As the occurrence and harm of plant diseases intensify, production and consumption of pesticides have increased year by year, and greatly contributed to the fertility of agriculture, but also brought a series of problems, such as the increase of drug resistance of plant pathogens and the excessive pesticide residues. In recent years, biopesticide, as characterized by environmentally safe due to low residual, safe to non-target organism due to better specificity and not as susceptible to produce drug resistance due to diverse work ways, has gained more attention than ever before and exhibited great development potential. Now much progress has been made about researches on new biogenic anti-plant-virus substances. The types of active components include proteins, polysaccharides and small molecules (alkaloids, flavonoids, phenols, essential oils) from plants, proteins and polysaccharides from microorganisms, polysaccharides from algae and oligochitosan from animals. This study summarized the research advance of biogenic anti-plant-virus substances in recent years and put forward their further development in the future.
Collapse
Affiliation(s)
- Lei Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Crop Pest Integrated Pest Management on Crop in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Chaohong Feng
- Institute of Plant Protection, Henan Academy of Agricultural Sciences, No. 116 Huayuan Road, Jinshui District, Zhengzhou, Henan Province 450002, China
| | - Kuan Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Crop Pest Integrated Pest Management on Crop in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Wenbao Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Crop Pest Integrated Pest Management on Crop in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yujia Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Crop Pest Integrated Pest Management on Crop in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xingan Hao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Crop Pest Integrated Pest Management on Crop in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yunfeng Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Crop Pest Integrated Pest Management on Crop in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| |
Collapse
|
14
|
Iraklis B, Kanda H, Nabeshima T, Onda M, Ota N, Koeda S, Hosokawa M. Digestion of chrysanthemum stunt viroid by leaf extracts of Capsicum chinense indicates strong RNA-digesting activity. PLANT CELL REPORTS 2016; 35:1617-28. [PMID: 27053224 DOI: 10.1007/s00299-016-1977-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/21/2016] [Indexed: 06/05/2023]
Abstract
KEY MESSAGE CSVd could not infect Nicotiana benthamiana when the plants were pretreated with crude leaf extract of Capsicum chinense 'Sy-2'. C. chinense leaves were revealed to contain strong RNA-digesting activity. Several studies have identified active antiviral and antiviroid agents in plants. Capsicum plants are known to contain antiviral agents, but the mechanism of their activity has not been determined. We aimed to elucidate the mechanism of Capsicum extract's antiviroid activity. Chrysanthemum stunt viroid (CSVd) was inoculated into Nicotiana benthamiana plants before or after treating the plants with a leaf extract of Capsicum chinense 'Sy-2'. CSVd infection was determined using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) 3 weeks after inoculation. When Capsicum extract was sprayed or painted onto N. benthamiana before inoculation, it was effective in preventing infection by CSVd. To evaluate CSVd digestion activity in leaf extracts, CSVd was mixed with leaf extracts of Mirabilis, Phytolacca, Pelargonium and Capsicum. CSVd-digesting activities were examined by quantifying undigested CSVd using qRT-PCR, and RNA gel blotting permitted visualization of the digested CSVd. Only Capsicum leaf extract digested CSVd, and in the Capsicum treatment, small digested CSVd products were detected by RNA gel blot analysis. When the digesting experiment was performed for various cultivars and species of Capsicum, only cultivars of C. chinense showed strong CSVd-digesting activity. Our observations indicated that Capsicum extract contains strong RNA-digesting activity, leading to the conclusion that this activity is the main mechanism for protection from infection by CSVd through spraying or painting before inoculation. To our knowledge, this is the first report of a strong RNA-digesting activity by a plant extract.
Collapse
Affiliation(s)
| | - Hiroko Kanda
- Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Tomoyuki Nabeshima
- Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Mayu Onda
- Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Nao Ota
- Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Sota Koeda
- Faculty of Agriculture, Kinki University, Nara, Nara, 631-8505, Japan
| | - Munetaka Hosokawa
- Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan.
| |
Collapse
|
15
|
Wang S, Li Z, Li S, Di R, Ho CT, Yang G. Ribosome-inactivating proteins (RIPs) and their important health promoting property. RSC Adv 2016. [DOI: 10.1039/c6ra02946a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Ribosome-inactivating proteins (RIPs), widely present in plants, certain fungi and bacteria, can inhibit protein synthesis by removing one or more specific adenine residues from the large subunit of ribosomal RNAs (rRNAs).
Collapse
Affiliation(s)
- Shuzhen Wang
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization
- Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains
- College of Life Science
- Huanggang Normal University
- Huanggang
| | - Zhiliang Li
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization
- Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains
- College of Life Science
- Huanggang Normal University
- Huanggang
| | - Shiming Li
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization
- Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains
- College of Life Science
- Huanggang Normal University
- Huanggang
| | - Rong Di
- Department of Plant Biology and Pathology
- Rutgers University
- New Brunswick
- USA
| | - Chi-Tang Ho
- Department of Food Science
- Rutgers University
- New Brunswick
- USA
| | - Guliang Yang
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization
- Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains
- College of Life Science
- Huanggang Normal University
- Huanggang
| |
Collapse
|
16
|
Di R, Tumer NE. Pokeweed antiviral protein: its cytotoxicity mechanism and applications in plant disease resistance. Toxins (Basel) 2015; 7:755-72. [PMID: 25756953 PMCID: PMC4379523 DOI: 10.3390/toxins7030755] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 02/11/2015] [Accepted: 03/02/2015] [Indexed: 11/16/2022] Open
Abstract
Pokeweed antiviral protein (PAP) is a 29 kDa type I ribosome inactivating protein (RIP) found in pokeweed plants. Pokeweed produces different forms of PAP. This review focuses on the spring form of PAP isolated from Phytolacca americana leaves. PAP exerts its cytotoxicity by removing a specific adenine from the α-sarcin/ricin loop of the large ribosomal RNA. Besides depurination of the rRNA, PAP has additional activities that contribute to its cytotoxicity. The mechanism of PAP cytotoxicity is summarized based on evidence from the analysis of transgenic plants and the yeast model system. PAP was initially found to be anti-viral when it was co-inoculated with plant viruses onto plants. Transgenic plants expressing PAP and non-toxic PAP mutants have displayed broad-spectrum resistance to both viral and fungal infection. The mechanism of PAP-induced disease resistance in transgenic plants is summarized.
Collapse
Affiliation(s)
- Rong Di
- Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA.
| | - Nilgun E Tumer
- Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA.
| |
Collapse
|
17
|
Domashevskiy AV, Goss DJ. Pokeweed antiviral protein, a ribosome inactivating protein: activity, inhibition and prospects. Toxins (Basel) 2015; 7:274-98. [PMID: 25635465 PMCID: PMC4344624 DOI: 10.3390/toxins7020274] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/07/2015] [Accepted: 01/23/2015] [Indexed: 01/30/2023] Open
Abstract
Viruses employ an array of elaborate strategies to overcome plant defense mechanisms and must adapt to the requirements of the host translational systems. Pokeweed antiviral protein (PAP) from Phytolacca americana is a ribosome inactivating protein (RIP) and is an RNA N-glycosidase that removes specific purine residues from the sarcin/ricin (S/R) loop of large rRNA, arresting protein synthesis at the translocation step. PAP is thought to play an important role in the plant's defense mechanism against foreign pathogens. This review focuses on the structure, function, and the relationship of PAP to other RIPs, discusses molecular aspects of PAP antiviral activity, the novel inhibition of this plant toxin by a virus counteraction-a peptide linked to the viral genome (VPg), and possible applications of RIP-conjugated immunotoxins in cancer therapeutics.
Collapse
MESH Headings
- Animals
- Binding Sites
- Endoribonucleases/chemistry
- Fungal Proteins/chemistry
- Genome, Viral
- Humans
- Protein Isoforms
- RNA Caps/chemistry
- RNA Caps/genetics
- RNA Caps/metabolism
- RNA, Plant/chemistry
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Ribosome Inactivating Proteins, Type 1/chemistry
- Ribosome Inactivating Proteins, Type 1/genetics
- Ribosome Inactivating Proteins, Type 1/metabolism
- Ribosome Inactivating Proteins, Type 1/pharmacology
- Ribosomes/chemistry
- Ribosomes/metabolism
- Ricin/chemistry
Collapse
Affiliation(s)
- Artem V Domashevskiy
- John Jay College of Criminal Justice, Department of Sciences, City University of New York, 524 West 59th Street, New York, NY 10019, USA.
| | - Dixie J Goss
- Department of Chemistry, Hunter College, City University of New York and the Graduate Center, 695 Park Avenue, New York, NY 10065, USA.
| |
Collapse
|
18
|
Di Maro A, Citores L, Russo R, Iglesias R, Ferreras JM. Sequence comparison and phylogenetic analysis by the Maximum Likelihood method of ribosome-inactivating proteins from angiosperms. PLANT MOLECULAR BIOLOGY 2014; 85:575-88. [PMID: 24880476 DOI: 10.1007/s11103-014-0204-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 05/16/2014] [Indexed: 05/16/2023]
Abstract
Ribosome-inactivating proteins (RIPs) from angiosperms are rRNA N-glycosidases that have been proposed as defence proteins against virus and fungi. They have been classified as type 1 RIPs, consisting of single-chain proteins, and type 2 RIPs, consisting of an A chain with RIP properties covalently linked to a B chain with lectin properties. In this work we have carried out a broad search of RIP sequence data banks from angiosperms in order to study their main structural characteristics and phylogenetic evolution. The comparison of the sequences revealed the presence, outside of the active site, of a novel structure that might be involved in the internal protein dynamics linked to enzyme catalysis. Also the B-chains presented another conserved structure that might function either supporting the beta-trefoil structure or in the communication between both sugar-binding sites. A systematic phylogenetic analysis of RIP sequences revealed that the most primitive type 1 RIPs were similar to that of the actual monocots (Poaceae and Asparagaceae). The primitive RIPs evolved to the dicot type 1 related RIPs (like those from Caryophyllales, Lamiales and Euphorbiales). The gene of a type 1 RIP related with the actual Euphorbiaceae type 1 RIPs fused with a double beta trefoil lectin gene similar to the actual Cucurbitaceae lectins to generate the type 2 RIPs and finally this gene underwent deletions rendering either type 1 RIPs (like those from Cucurbitaceae, Rosaceae and Iridaceae) or lectins without A chain (like those from Adoxaceae).
Collapse
Affiliation(s)
- Antimo Di Maro
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, 81100, Caserta, Italy
| | | | | | | | | |
Collapse
|
19
|
Domashevskiy AV, Miyoshi H, Goss DJ. Inhibition of pokeweed antiviral protein (PAP) by turnip mosaic virus genome-linked protein (VPg). J Biol Chem 2012; 287:29729-38. [PMID: 22773840 DOI: 10.1074/jbc.m112.367581] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pokeweed antiviral protein (PAP) from Phytolacca americana is a ribosome-inactivating protein (RIP) and an RNA N-glycosidase that removes specific purine residues from the sarcin/ricin loop of large rRNA, arresting protein synthesis at the translocation step. PAP is also a cap-binding protein and is a potent antiviral agent against many plant, animal, and human viruses. To elucidate the mechanism of RNA depurination, and to understand how PAP recognizes and targets various RNAs, the interactions between PAP and turnip mosaic virus genome-linked protein (VPg) were investigated. VPg can function as a cap analog in cap-independent translation and potentially target PAP to uncapped IRES-containing RNA. In this work, fluorescence spectroscopy and HPLC techniques were used to quantitatively describe PAP depurination activity and PAP-VPg interactions. PAP binds to VPg with high affinity (29.5 nm); the reaction is enthalpically driven and entropically favored. Further, VPg is a potent inhibitor of PAP depurination of RNA in wheat germ lysate and competes with structured RNA derived from tobacco etch virus for PAP binding. VPg may confer an evolutionary advantage by suppressing one of the plant defense mechanisms and also suggests the possible use of this protein against the cytotoxic activity of ribosome-inactivating proteins.
Collapse
Affiliation(s)
- Artem V Domashevskiy
- Department of Chemistry, Hunter College and the Graduate Center of the City University of New York, New York, NY 10065, USA
| | | | | |
Collapse
|
20
|
Goktepe I, Maness L, Hardy B, Yu J, Ahmedna M. Antiproliferative and Apoptotic Effects of Phytolacca americana Extracts and their Fractions on Breast and Colon Cancer Cells. ACTA ACUST UNITED AC 2012. [DOI: 10.3923/rjmp.2012.17.26] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
21
|
Karran RA, Hudak KA. Depurination of Brome mosaic virus RNA3 inhibits its packaging into virus particles. Nucleic Acids Res 2011; 39:7209-22. [PMID: 21609957 PMCID: PMC3167629 DOI: 10.1093/nar/gkr383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Packaging of the segmented RNA genome of Brome mosaic virus (BMV) into discrete particles is an essential step in the virus life cycle; however, questions remain regarding the mechanism of RNA packaging and the degree to which the viral coat protein controls the process. In this study, we used a plant-derived glycosidase, Pokeweed antiviral protein, to remove 14 specific bases from BMV RNA3 to examine the effect of depurination on virus assembly. Depurination of A771 within ORF3 and A1006 in the intergenic region inhibited coat protein binding and prevented RNA3 incorporation into particles. The disruption of interaction was not based on sequence identity, as mutation of these two purines to pyrimidines did not decrease coat protein-binding affinity. Rather, we suggest that base removal results in decreased thermodynamic stability of local RNA structures required for packaging, and that this instability is detected by coat protein. These results describe a new level of discrimination by coat protein, whereby it recognizes damage to specific viral RNA elements in the form of base removal and selects against incorporating the RNA into particles.
Collapse
Affiliation(s)
- Rajita A Karran
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada
| | | |
Collapse
|
22
|
Sztuba-Solińska J, Stollar V, Bujarski JJ. Subgenomic messenger RNAs: mastering regulation of (+)-strand RNA virus life cycle. Virology 2011; 412:245-55. [PMID: 21377709 PMCID: PMC7111999 DOI: 10.1016/j.virol.2011.02.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/14/2010] [Accepted: 02/04/2011] [Indexed: 12/12/2022]
Abstract
Many (+)-strand RNA viruses use subgenomic (SG) RNAs as messengers for protein expression, or to regulate their viral life cycle. Three different mechanisms have been described for the synthesis of SG RNAs. The first mechanism involves internal initiation on a (−)-strand RNA template and requires an internal SGP promoter. The second mechanism makes a prematurely terminated (−)-strand RNA which is used as template to make the SG RNA. The third mechanism uses discontinuous RNA synthesis while making the (−)-strand RNA templates. Most SG RNAs are translated into structural proteins or proteins related to pathogenesis: however other SG RNAs regulate the transition between translation and replication, function as riboregulators of replication or translation, or support RNA–RNA recombination. In this review we discuss these functions of SG RNAs and how they influence viral replication, translation and recombination.
Collapse
Affiliation(s)
- Joanna Sztuba-Solińska
- Plant Molecular Biology Center and the Department of Biological Sciences, Northern Illinois University, De Kalb, IL 60115, USA
| | | | | |
Collapse
|
23
|
Tourlakis ME, Karran RA, Desouza L, Siu KWM, Hudak KA. Homodimerization of pokeweed antiviral protein as a mechanism to limit depurination of pokeweed ribosomes. MOLECULAR PLANT PATHOLOGY 2010; 11:757-767. [PMID: 21029321 PMCID: PMC6640456 DOI: 10.1111/j.1364-3703.2010.00640.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ribosome inactivating proteins are glycosidases synthesized by many plants and have been hypothesized to serve in defence against pathogens. These enzymes catalytically remove a conserved purine from the sarcin/ricin loop of the large ribosomal RNA, which has been shown in vitro to limit protein synthesis. The resulting toxicity suggests that plants may possess a mechanism to protect their ribosomes from depurination during the synthesis of these enzymes. For example, pokeweed antiviral protein (PAP) is cotranslationally inserted into the lumen of the endoplasmic reticulum and travels via the endomembrane system to be stored in the cell wall. However, some PAP may retrotranslocate across the endoplasmic reticulum membrane to be released back into the cytosol, thereby exposing ribosomes to depurination. In this work, we isolated and characterized a complexed form of the enzyme that exhibits substantially reduced activity. We showed that this complex is a homodimer of PAP and that dimerization involves a peptide that contains a conserved aromatic amino acid, tyrosine 123, located in the active site of the enzyme. Bimolecular fluorescence complementation demonstrated that the homodimer may form in vivo and that dimerization is prevented by the substitution of tyrosine 123 for alanine. The homodimer is a minor form of PAP, observed only in the cytosol of cells and not in the apoplast. Taken together, these data support a novel mechanism for the limitation of depurination of autologous ribosomes by molecules of the protein that escape transport to the cell wall by the endomembrane system.
Collapse
|
24
|
Mansouri S, Choudhary G, Sarzala PM, Ratner L, Hudak KA. Suppression of human T-cell leukemia virus I gene expression by pokeweed antiviral protein. J Biol Chem 2009; 284:31453-62. [PMID: 19748897 DOI: 10.1074/jbc.m109.046235] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human T-cell leukemia virus I (HTLV-I) is a deltaretrovirus that is the causative agent of adult T-cell leukemia and the neurological disorder HTLV-I-associated myelopathy/tropical spastic paraparesis. Currently, no effective antiretroviral treatment options are available to restrict the development of diseases associated with the virus. In this work, we investigated the activity of pokeweed antiviral protein (PAP) on HTLV-I, when expressed from a proviral clone in 293T cells or in an HTLV-I immortalized cell line. PAP is a plant-derived N-glycosidase that exhibits antiviral activity against a number of viruses; however, its mode of action has not been clearly defined. Here, we describe the mechanism by which PAP inhibited production of HTLV-I. We show that PAP depurinated nucleotides within the gag open reading frame and suppressed the synthesis of viral proteins in part by decreasing the translational efficiency of HTLV-I gag/pol mRNA. Observed reduction in levels of viral mRNAs were not due to enhanced degradation; rather, decreased amounts of viral transactivator protein, Tax, led to feed-back inhibition of transcription from the viral promoter. Therefore, PAP efficiently suppressed HTLV-I gene expression at both translational and transcriptional levels, resulting in substantially diminished virus production. Significantly, no changes in viability or rates of cellular transcription or translation were observed in cells expressing PAP, indicating that this protein was not toxic. Antiviral activity, together with the absence of cytotoxicity, supports further investigation of this enzyme as a novel therapeutic agent against the progression of HTLV-I infection.
Collapse
Affiliation(s)
- Sheila Mansouri
- Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada
| | | | | | | | | |
Collapse
|
25
|
Karran RA, Hudak KA. Depurination within the intergenic region of Brome mosaic virus RNA3 inhibits viral replication in vitro and in vivo. Nucleic Acids Res 2008; 36:7230-9. [PMID: 19004869 PMCID: PMC2602774 DOI: 10.1093/nar/gkn896] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pokeweed antiviral protein (PAP) is a glycosidase of plant origin that has been shown to depurinate some viral RNAs in vitro. We have demonstrated previously that treatment of Brome mosaic virus (BMV) RNAs with PAP inhibited their translation in a cell-free system and decreased their accumulation in barley protoplasts. In the current study, we map the depurination sites on BMV RNA3 and describe the mechanism by which replication of the viral RNA is inhibited by depurination. Specifically, we demonstrate that the viral replicase exhibited reduced affinity for depurinated positive-strand RNA3 compared with intact RNA3, resulting in less negative-strand product. This decrease was due to depurination within the intergenic region of RNA3, between ORF3 and 4, and distant from the 3′ terminal core promoter required for initiation of negative-strand RNA synthesis. Depurination within the intergenic region alone inhibited the binding of the replicase to full-length RNA3, whereas depurination outside the intergenic region permitted the replicase to initiate negative-strand synthesis; however, elongation of the RNA product was stalled at the abasic nucleotide. These results support a role of the intergenic region in controlling negative-strand RNA synthesis and contribute new insight into the effect of depurination by PAP on BMV replication.
Collapse
Affiliation(s)
- Rajita A Karran
- Department of Biology, York University, Toronto, Ontario, Canada
| | | |
Collapse
|
26
|
Gandhi R, Manzoor M, Hudak KA. Depurination of Brome mosaic virus RNA3 in vivo results in translation-dependent accelerated degradation of the viral RNA. J Biol Chem 2008; 283:32218-28. [PMID: 18815133 DOI: 10.1074/jbc.m803785200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pokeweed antiviral protein (PAP) is a ribosome-inactivating protein isolated from the pokeweed plant (Phytolacca americana) that exhibits antiviral activity against several plant and animal viruses. We have shown previously that PAP depurinates Brome mosaic virus (BMV) RNAs in vitro and that prior incubation of these RNAs with PAP reduced their synthesis in barley protoplasts. To investigate the post-transcriptional effect of PAP on viral RNA in vivo, we transcribed BMV RNA3 and expressed PAP in the yeast, Saccharomyces cerevisiae, which is a surrogate host for BMV. With an inducible transcription system, we show that the half-life of RNA3 in PAP-expressing cells was significantly less than in cells expressing PAPx, its enzymatically inactive form. PAP bound to RNA3 and depurinated the RNA within open reading frames 3 and 4 and within untranslated regions of the RNA. The depurinated RNA was associated with polysomes, caused ribosomes to stall at the point of depurination, and was targeted for accelerated degradation by components of the No-go decay pathway. As a consequence of translation elongation arrest and increased RNA degradation, expression of PAP in yeast also decreased the level of protein 3a, encoded by the 5'-proximal open reading frame 3 of BMV RNA3. These data provide the first evidence of viral RNA depurination in vivo by any ribosome-inactivating protein and support our hypothesis that depurination contributes to the antiviral activity of PAP, by enhancing viral RNA degradation and reducing translation of viral protein product.
Collapse
Affiliation(s)
- Rikesh Gandhi
- Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada
| | | | | |
Collapse
|
27
|
He YW, Guo CX, Pan YF, Peng C, Weng ZH. Inhibition of hepatitis B virus replication by pokeweed antiviral protein in vitro. World J Gastroenterol 2008; 14:1592-7. [PMID: 18330954 PMCID: PMC2693758 DOI: 10.3748/wjg.14.1592] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the inhibitory effects of pokeweed antiviral protein seed (PAP-S) and PAP encoded by a eukaryotic expression plasmid on hepatitis B virus (HBV) replication in vitro.
METHODS: HepG2 2.2.15 cells in cultured medium were treated with different concentrations of PAP-S. HBsAg, HBeAg and HBV DNA in supernatants were determined by ELISA and fluorescent quantitative PCR respectively. MTT method was used to assay for cytotoxicity. HepG2 were cotransfected with various amounts of PAP encoded by a eukaryotic expression plasmid and replication competent wild-type HBV 1.3 fold over-length plasmid. On d 3 after transfection, HBsAg and HBeAg were determined by using ELISA. Levels of HBV core-associated DNA and RNA were detected by using Southern and Northern blot, respectively.
RESULTS: The inhibitory effects of PAP-S on HBsAg, HBeAg and HBV DNA were gradually enhanced with the increase of PAP concentration. When the concentration of PAP-S was 10 &mgr;g/mL, the inhibition rates of HBsAg, HBeAg and HBV DNA were 20.9%, 30.2% and 50%, respectively. After transfection of 1.0 &mgr;g and 2.0 &mgr;g plasmid pXF3H-PAP, the levels of HBV nucleocapside-associated DNA were reduced by 38.0% and 74.0% respectively, the levels of HBsAg in the media by 76.8% and 99.7% respectively, and the levels of HBeAg by 72.7% and 99.3% respectively as compared with controls. Transfection with 2 &mgr;g plasmid pXF3H-PAP reduced the levels of HBV nucleocapside-associated RNA by 69.0%.
CONCLUSION: Both PAP-S and PAP encoded by a eukaryotic expression plasmid could effectively inhibit HBV replication and antigen expression in vitro, and the inhibitory effects were dose-dependent.
Collapse
|
28
|
Parikh BA, Tortora A, Li XP, Tumer NE. Ricin inhibits activation of the unfolded protein response by preventing splicing of the HAC1 mRNA. J Biol Chem 2008; 283:6145-53. [PMID: 18180297 PMCID: PMC3024914 DOI: 10.1074/jbc.m707981200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ricin A chain (RTA) inhibits protein synthesis by removing a specific adenine from the highly conserved alpha-sarcin/ricin loop in the large rRNA. Expression of RTA with its own signal sequence in yeast resulted in its translocation into the endoplasmic reticulum (ER) and subsequent glycosylation. Because RTA must unfold within the ER, it may be vulnerable to host defenses, such as the unfolded protein response (UPR). UPR was induced in cells expressing an active site mutant but not the wild type RTA, indicating that the active site of RTA played a role in perturbing the ER stress response. The inactive RTA without the signal sequence did not induce UPR, indicating that translocation into the ER was critical for induction of UPR. The wild type RTA inhibited activation of UPR not only due to ER stress induced by the protein itself but also by global effectors such as tunicamycin and dithiothreitol. Mature RTA without the signal sequence also inhibited UPR, providing evidence that inhibition of UPR occurred on the cytosolic face of the ER. RTA could not inhibit UPR when the spliced form of HAC1 mRNA was provided in trans, indicating that it had a direct effect on UPR upstream of HAC1-dependent transcriptional activation. Only the precursor form of HAC1 mRNA was detected in cells expressing RTA after exposure to ER stress, demonstrating that ricin inhibits activation of UPR by preventing HAC1 mRNA splicing. The RTA mutants that depurinated ribosomes but did not kill cells were not able to inhibit activation of UPR by tunicamycin, providing evidence that the inability to activate UPR in response to ER stress contributes to the cytotoxicity of ricin.
Collapse
Affiliation(s)
- Bijal A. Parikh
- Biotechnology Center for Agriculture and the Environment and the Department of Plant Biology and Pathology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey 08901-8520
| | | | - Xiao-Ping Li
- Biotechnology Center for Agriculture and the Environment and the Department of Plant Biology and Pathology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey 08901-8520
| | - Nilgun E. Tumer
- Biotechnology Center for Agriculture and the Environment and the Department of Plant Biology and Pathology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey 08901-8520
| |
Collapse
|
29
|
Palani PV, Lin NS. Northern analysis of viral plus- and minus-strand RNAs. CURRENT PROTOCOLS IN MICROBIOLOGY 2007; Chapter 16:Unit 16E.3. [PMID: 18770617 DOI: 10.1002/9780471729259.mc16e03s4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Replication is a fundamental activity of viruses. Replication of positive-sense RNA viruses involves the synthesis of complementary minus-strand intermediates from the parental RNA template followed by synthesis of nascent plus strands. Negative-sense RNA genome and double-stranded RNA are copied into positive-sense mRNA before translation. To detect and estimate the abundance of plus- and minus-strand viral transcripts in the infected samples, northern analysis is the most commonly used method.
Collapse
|
30
|
Wang M, Hudak KA. A novel interaction of pokeweed antiviral protein with translation initiation factors 4G and iso4G: a potential indirect mechanism to access viral RNAs. Nucleic Acids Res 2006; 34:1174-81. [PMID: 16493141 PMCID: PMC1380256 DOI: 10.1093/nar/gkj520] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pokeweed antiviral protein (PAP) is a ribosome inactivating protein recognized primarily for its ability to depurinate the sarcin/ricin loop of the large rRNA. Studies have demonstrated that PAP also depurinates other RNA templates, such as Human immunodeficiency virus-1 RNA and Brome mosaic virus RNAs. However, the mechanism by which PAP accesses viral RNAs is not known. Considering that PAP was shown recently to bind the m(7)G of the cap structure, we speculated that PAP may interact with other factors involved in translation initiation. By far western analysis, we show that PAP binds specifically to eIF4G and eIFiso4G of wheat germ and analysis with truncation mutants of eIFiso4G indicates that a region of this protein, between amino acids 511 and 624, is required for PAP binding activity. The yeast two-hybrid system supports these results by showing reduced growth and alpha-galactosidase expression with truncation in this region of eIFiso4G. PAP binds m(7)GTP-Sepharose and this interaction does not diminish the binding of PAP to purified eIFiso4G, indicating that a complex can form among the cap structure, PAP and eIFiso4G. We incubated PAP with uncapped and non-polyadenylated transcripts containing a 3' translation enhancer sequence (TE) known to increase translation of the RNA in an eIF4F dependent manner. We show that in the presence of wheat germ lysate, PAP depurinates the uncapped and non-polyadenylated transcripts containing a functional wild-type 3'TE, but does not depurinate messages containing a non-functional mutant 3'TE. These results support our hypothesis that binding of PAP to eIF4G and eIFiso4G can provide a mechanism for PAP to access both uncapped and capped viral RNAs for depurination.
Collapse
Affiliation(s)
| | - K. A. Hudak
- To whom correspondence should be addressed at Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada. Tel: +1 416 736 2100, ext. 33470; Fax: +1 416 736 5698;
| |
Collapse
|