1
|
Torralba B, Blanc S, Michalakis Y. Reassortments in single-stranded DNA multipartite viruses: Confronting expectations based on molecular constraints with field observations. Virus Evol 2024; 10:veae010. [PMID: 38384786 PMCID: PMC10880892 DOI: 10.1093/ve/veae010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/23/2023] [Accepted: 01/30/2024] [Indexed: 02/23/2024] Open
Abstract
Single-stranded DNA multipartite viruses, which mostly consist of members of the genus Begomovirus, family Geminiviridae, and all members of the family Nanoviridae, partly resolve the cost of genomic integrity maintenance through two remarkable capacities. They are able to systemically infect a host even when their genomic segments are not together in the same host cell, and these segments can be separately transmitted by insect vectors from host to host. These capacities potentially allow such viruses to reassort at a much larger spatial scale, since reassortants could arise from parental genotypes that do not co-infect the same cell or even the same host. To assess the limitations affecting reassortment and their implications in genome integrity maintenance, the objective of this review is to identify putative molecular constraints influencing reassorted segments throughout the infection cycle and to confront expectations based on these constraints with empirical observations. Trans-replication of the reassorted segments emerges as the major constraint, while encapsidation, viral movement, and transmission compatibilities appear more permissive. Confronting the available molecular data and the resulting predictions on reassortments to field population surveys reveals notable discrepancies, particularly a surprising rarity of interspecific natural reassortments within the Nanoviridae family. These apparent discrepancies unveil important knowledge gaps in the biology of ssDNA multipartite viruses and call for further investigation on the role of reassortment in their biology.
Collapse
Affiliation(s)
- Babil Torralba
- PHIM, Université Montpellier, IRD, CIRAD, INRAE, Institut Agro, Avenue du Campus d’Agropolis - ZAC de Baillarguet, Montpellier 34980, France
| | - Stéphane Blanc
- PHIM, Université Montpellier, IRD, CIRAD, INRAE, Institut Agro, Avenue du Campus d’Agropolis - ZAC de Baillarguet, Montpellier 34980, France
| | - Yannis Michalakis
- MIVEGEC, Université Montpellier, CNRS, IRD, 911, Avenue Agropolis, Montpellier 34394, France
| |
Collapse
|
2
|
Li F, Xi K, Li Y, Ming T, Huang Y, Zhang L. Genome-wide analysis of transmembrane 9 superfamily genes in wheat ( Triticum aestivum) and their expression in the roots under nitrogen limitation and Bacillus amyloliquefaciens PDR1 treatment conditions. FRONTIERS IN PLANT SCIENCE 2024; 14:1324974. [PMID: 38259936 PMCID: PMC10800943 DOI: 10.3389/fpls.2023.1324974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/19/2023] [Indexed: 01/24/2024]
Abstract
Introduction Transmembrane 9 superfamily (TM9SF) proteins play significant roles in plant physiology. However, these proteins are poorly characterized in wheat (Triticum aestivum). The present study aimed at the genome-wide analysis of putative wheat TM9SF (TraesTM9SF) proteins and their potential involvement in response to nitrogen limitation and Bacillus amyloliquefaciens PDR1 treatments. Methods TraesTM9SF genes were retrieved from the wheat genome, and their physiochemical properties, alignment, phylogenetic, motif structure, cis-regulatory element, synteny, protein-protein interaction (PPI), and transcription factor (TF) prediction analyses were performed. Transcriptome sequencing and quantitative real-time polymerase reaction (qRT-PCR) were performed to detect gene expression in roots under single or combined treatments with nitrogen limitation and B. amyloliquefaciens PDR1. Results and discussion Forty-seven TraesTM9SF genes were identified in the wheat genome, highlighting the significance of these genes in wheat. TraesTM9SF genes were absent on some wheat chromosomes and were unevenly distributed on the other chromosomes, indicating that potential regulatory functions and evolutionary events may have shaped the TraesTM9SF gene family. Fifty-four cis-regulatory elements, including light-response, hormone response, biotic/abiotic stress, and development cis-regulatory elements, were present in the TraesTM9SF promoter regions. No duplication of TraesTM9SF genes in the wheat genome was recorded, and 177 TFs were predicted to target the 47 TraesTM9SF genes in a complex regulatory network. These findings offer valued data for predicting the putative functions of uncharacterized TM9SF genes. Moreover, transcriptome analysis and validation by qRT-PCR indicated that the TraesTM9SF genes are expressed in the root system of wheat and are potentially involved in the response of this plant to single or combined treatments with nitrogen limitation and B. amyloliquefaciens PDR1, suggesting their functional roles in plant growth, development, and stress responses. Conclusion These findings may be vital in further investigation of the function and biological applications of TM9SF genes in wheat.
Collapse
Affiliation(s)
- Fei Li
- The Key Laboratory of Biodiversity Conservation in Karst Mountain Area of Southwest of China, Forestry Ministry, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Kuanling Xi
- The Key Laboratory of Biodiversity Conservation in Karst Mountain Area of Southwest of China, Forestry Ministry, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Yuke Li
- The Key Laboratory of Biodiversity Conservation in Karst Mountain Area of Southwest of China, Forestry Ministry, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Tang Ming
- The Key Laboratory of Biodiversity Conservation in Karst Mountain Area of Southwest of China, Forestry Ministry, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Yufeng Huang
- The Key Laboratory of Biodiversity Conservation in Karst Mountain Area of Southwest of China, Forestry Ministry, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Lijun Zhang
- Science and Technology Division, Guizhou Normal University, Guiyang, China
| |
Collapse
|
3
|
Jain H, Singh I, Chahal S, Kaur R, Siwach P. Phylogenetic and recombination analysis of Begomoviruses associated with Cotton leaf curl disease and in silico analysis of viral-host protein interactions. Microb Pathog 2024; 186:106504. [PMID: 38122873 DOI: 10.1016/j.micpath.2023.106504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 12/23/2023]
Abstract
Cotton leaf curl disease (CLCuD), caused by numerous begomoviruses (BGVs), is a highly disastrous disease in cotton crops worldwide. To date, several efforts have shown limited success in controlling this disease. CLCuD-associated BGVs (CABs) are known for their high rate of intra and interspecific recombinations, which raises an urgent need to find an efficient and conserved target region to combat disease. In the present study, phylogenetic analysis of selected 11 CABs, along with associated alphasatellites, and betasatellites revealed a close evolutionary relationship among them. Recombination analysis of 1374 isolates of CABs revealed 54 recombination events for the major players of CLCuD in cotton and the Cotton leaf curl Multan virus (CLCuMuV) as the most recombinant CAB. Recombination breakpoints were frequent in all regions except C2 and C3. C3-encoded protein, known as viral replication enhancer (REn), promotes viral replication by enhancing the activity of replicase (Rep) protein. Both proteins were found to contain significantly conserved domains and motifs. The identified motifs were found crucial for their interaction with host protein PCNA (Proliferating cell nuclear antigen), facilitating viral replication. Interruption at the REn-PCNA and Rep-PCNA interactions by targeting the identified conserved motifs is proposed as a prospect to halt viral replication, after suitable experimental validation.
Collapse
Affiliation(s)
- Heena Jain
- Department of Biotechnology, Chaudhary Devi Lal University, Sirsa, 125055, Haryana, India
| | - Inderjeet Singh
- Department of Biotechnology, Chaudhary Devi Lal University, Sirsa, 125055, Haryana, India
| | - Shiwani Chahal
- Department of Biotechnology, Chaudhary Devi Lal University, Sirsa, 125055, Haryana, India
| | - Ramandeep Kaur
- Department of Biotechnology, Chaudhary Devi Lal University, Sirsa, 125055, Haryana, India
| | - Priyanka Siwach
- Department of Biotechnology, Chaudhary Devi Lal University, Sirsa, 125055, Haryana, India.
| |
Collapse
|
4
|
Nogueira AM, Barbosa TMC, Quadros AFF, Orílio AF, Bigão MCJ, Xavier CAD, Ferro CG, Zerbini FM. Specific Nucleotides in the Common Region of the Begomovirus Tomato Rugose Mosaic Virus (ToRMV) Are Responsible for the Negative Interference over Tomato Severe Rugose Virus (ToSRV) in Mixed Infection. Viruses 2023; 15:2074. [PMID: 37896851 PMCID: PMC10611410 DOI: 10.3390/v15102074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/08/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Mixed infection between two or more begomoviruses is commonly found in tomato fields and can affect disease outcomes by increasing symptom severity and viral accumulation compared with single infection. Viruses that affect tomato include tomato severe rugose virus (ToSRV) and tomato rugose mosaic virus (ToRMV). Previous work showed that in mixed infection, ToRMV negatively affects the infectivity and accumulation of ToSRV. ToSRV and ToRMV share a high degree of sequence identity, including cis-elements in the common region (CR) and their specific recognition sites (iteron-related domain, IRD) within the Rep gene. Here, we investigated if divergent sites in the CR and IRD are involved in the interaction between these two begomoviruses. ToSRV clones were constructed containing the same nucleotides as ToRMV in the CR (ToSRV-A(ToR:CR)), IRD (ToSRV-A(ToR:IRD)) and in both regions (ToSRV-A(ToR:CR+IRD)). When plants were co-inoculated with ToRMV and ToSRV-A(ToR:IRD), the infectivity and accumulation of ToSRV were negatively affected. In mixed inoculation of ToRMV with ToSRV-A(ToR:CR), high infectivity of both viruses and high DNA accumulation of ToSRV-A(ToR:CR) were observed. A decrease in viral accumulation was observed in plants inoculated with ToSRV-A(ToR:CR+IRD). These results indicate that differences in the CR, but not the IRD, are responsible for the negative interference of ToRMV on ToSRV.
Collapse
Affiliation(s)
- Angélica M. Nogueira
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
- Departamento de Proteção Vegetal, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), Botucatu 18610-307, SP, Brazil
| | - Tarsiane M. C. Barbosa
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
- Departamento de Entomologia e Acarologia, ESALQ, Universidade de São Paulo, Piracicaba 13418-900, SP, Brazil
| | - Ayane F. F. Quadros
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
| | - Anelise F. Orílio
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
| | - Marcela C. J. Bigão
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
| | - César A. D. Xavier
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| | - Camila G. Ferro
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
- Departamento de Fitopatologia e Nematologia, ESALQ, Universidade de São Paulo, Piracicaba 13418-900, SP, Brazil
| | - Francisco Murilo Zerbini
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (A.M.N.); (T.M.C.B.); (A.F.F.Q.); (A.F.O.); (M.C.J.B.); (C.A.D.X.); (C.G.F.)
- Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
| |
Collapse
|
5
|
Shakir S, Mubin M, Nahid N, Serfraz S, Qureshi MA, Lee TK, Liaqat I, Lee S, Nawaz-ul-Rehman MS. REPercussions: how geminiviruses recruit host factors for replication. Front Microbiol 2023; 14:1224221. [PMID: 37799604 PMCID: PMC10548238 DOI: 10.3389/fmicb.2023.1224221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/21/2023] [Indexed: 10/07/2023] Open
Abstract
Circular single-stranded DNA viruses of the family Geminiviridae encode replication-associated protein (Rep), which is a multifunctional protein involved in virus DNA replication, transcription of virus genes, and suppression of host defense responses. Geminivirus genomes are replicated through the interaction between virus Rep and several host proteins. The Rep also interacts with itself and the virus replication enhancer protein (REn), which is another essential component of the geminivirus replicase complex that interacts with host DNA polymerases α and δ. Recent studies revealed the structural and functional complexities of geminivirus Rep, which is believed to have evolved from plasmids containing a signature domain (HUH) for single-stranded DNA binding with nuclease activity. The Rep coding sequence encompasses the entire coding sequence for AC4, which is intricately embedded within it, and performs several overlapping functions like Rep, supporting virus infection. This review investigated the structural and functional diversity of the geminivirus Rep.
Collapse
Affiliation(s)
- Sara Shakir
- Plant Genetics Lab, Gembloux Agro-Bio Tech, University of Liѐge, Gembloux, Belgium
| | - Muhammad Mubin
- Virology Lab, Center for Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Faisalabad, Pakistan
| | - Nazia Nahid
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
| | - Saad Serfraz
- Virology Lab, Center for Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Faisalabad, Pakistan
| | - Muhammad Amir Qureshi
- Department of Integrative Biotechnology, Sungkyunkwan University, Suwon, Republic of Korea
| | - Taek-Kyun Lee
- Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, Geoje, Republic of Korea
| | - Iram Liaqat
- Microbiology Lab, Department of Zoology, Government College University, Lahore, Pakistan
| | - Sukchan Lee
- Department of Integrative Biotechnology, Sungkyunkwan University, Suwon, Republic of Korea
| | - Muhammad Shah Nawaz-ul-Rehman
- Virology Lab, Center for Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Faisalabad, Pakistan
| |
Collapse
|
6
|
Ren R, Zheng L, Han J, Perdoncini Carvalho C, Miyashita S, Zhang D, Qu F. Intracellular bottlenecking permits no more than three tomato yellow leaf curl virus genomes to initiate replication in a single cell. PLoS Pathog 2023; 19:e1011365. [PMID: 37126519 PMCID: PMC10174518 DOI: 10.1371/journal.ppat.1011365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 05/11/2023] [Accepted: 04/17/2023] [Indexed: 05/02/2023] Open
Abstract
Viruses are constantly subject to natural selection to enrich beneficial mutations and weed out deleterious ones. However, it remains unresolved as to how the phenotypic gains or losses brought about by these mutations cause the viral genomes carrying the very mutations to become more or less numerous. Previous investigations by us and others suggest that viruses with plus strand (+) RNA genomes may compel such selection by bottlenecking the replicating genome copies in each cell to low single digits. Nevertheless, it is unclear if similarly stringent reproductive bottlenecks also occur in cells invaded by DNA viruses. Here we investigated whether tomato yellow leaf curl virus (TYLCV), a small virus with a single-stranded DNA genome, underwent population bottlenecking in cells of its host plants. We engineered a TYLCV genome to produce two replicons that express green fluorescent protein and mCherry, respectively, in a replication-dependent manner. We found that among the cells entered by both replicons, less than 65% replicated both, whereas at least 35% replicated either of them alone. Further probability computation concluded that replication in an average cell was unlikely to have been initiated with more than three replicon genome copies. Furthermore, sequential inoculations unveiled strong mutual exclusions of these two replicons at the intracellular level. In conclusion, the intracellular population of the small DNA virus TYLCV is actively bottlenecked, and such bottlenecking may be a virus-encoded, evolutionarily conserved trait that assures timely selection of new mutations emerging through error-prone replication.
Collapse
Affiliation(s)
- Ruifan Ren
- Longping Branch, College of Biology, Hunan University, Changsha, China
- Department of Plant Pathology, The Ohio State University, Wooster, Ohio, United States of America
- Hunan Plant Protection Institute, Changsha, China
| | - Limin Zheng
- Department of Plant Pathology, The Ohio State University, Wooster, Ohio, United States of America
| | - Junping Han
- Department of Plant Pathology, The Ohio State University, Wooster, Ohio, United States of America
| | | | - Shuhei Miyashita
- Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Deyong Zhang
- Longping Branch, College of Biology, Hunan University, Changsha, China
- Hunan Plant Protection Institute, Changsha, China
| | - Feng Qu
- Department of Plant Pathology, The Ohio State University, Wooster, Ohio, United States of America
| |
Collapse
|
7
|
Wang C, Fan S, Xu N, Li Z, Zhang S, Zhu S. Structural basis of DNA recognition of tomato yellow leaf curl virus replication-associated protein. Int J Biol Macromol 2022; 205:316-328. [PMID: 35192905 DOI: 10.1016/j.ijbiomac.2022.02.106] [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: 11/22/2021] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 11/05/2022]
Abstract
Conserved and multifunctional Geminivirus Replication-associated Protein (Rep) specifically recognizes the replication origin and initiates viral DNA replication. We report the X-ray crystallography-based structures of two complexes containing the N-terminal domain (5-117aa) of Tomato yellow leaf curl virus (TYLCV) Rep: the catalytically-dead Rep in complex with nonanucleotide ssDNA (Rep5-117 Y101F-ssDNA) as well as the catalytically-active phosphotyrosine covalent adduct (Rep5-117-ssDNA). These structures provide functional insight into the role of Rep in viral replication. Metal ions stabilize the DNA conformation by interacting with the phosphate group of adenine and thus promote formation of the catalytic center. Furthermore, we identified a compound that inhibits the binding of Rep to ssDNA and dsDNA and found that the addition of metal ions compromises the inhibitory effectiveness of this compound. This study demonstrates the mechanism of DNA recognition and cleavage process of viral Rep, emphasizing the role of metal ions.
Collapse
Affiliation(s)
- Chaonan Wang
- College of Plant Protection, China Agricultural University, Beijing 100193, China; Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Shilong Fan
- The Technology Center for Protein Sciences, Tsinghua University, Beijing 100084, China
| | - Ning Xu
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhihong Li
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Senyan Zhang
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing 100176, China.
| | - Shuifang Zhu
- College of Plant Protection, China Agricultural University, Beijing 100193, China; Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing 100176, China.
| |
Collapse
|
8
|
Zakeel MCM, Geering ADW, Thomas JE, Akinsanmi OA. Characterisation of novel endogenous geminiviral elements in macadamia. BMC Genomics 2021; 22:858. [PMID: 34837949 PMCID: PMC8626973 DOI: 10.1186/s12864-021-08174-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 11/11/2021] [Indexed: 11/11/2022] Open
Abstract
Background The presence of geminivirus sequences in a preliminary analysis of sRNA sequences from the leaves of macadamia trees with abnormal vertical growth (AVG) syndrome was investigated. Results A locus of endogenous geminiviral elements (EGE) in the macadamia genome was analysed, and the sequences revealed a high level of deletions and/or partial integrations, thus rendering the EGE transcriptionally inactive. The replication defective EGE in the macadamia genome indicates its inability to be the source of new viral infections and thus cause AVG or any other disease in macadamia. The EGE sequences were detected in two edible Macadamia species that constitute commercial cultivars and the wild germplasm of edible and inedible species of Macadamia. This strongly suggests that the integration preceded speciation of the genus Macadamia. A draft genome of a locus of EGE in Macadamia was developed. The findings of this study provide evidence to suggest the endogenization of the geminiviral sequences in the macadamia genome and the ancestral relationship of EGE with Macadamia in the Proteaceae family. Random mutations accumulating in the EGE inform that the sequence is evolving. Conclusions The EGE in Macadamia is inactive and thus not a direct cause of any diseases or syndromes including AVG in macadamia. The insertion of the EGE in the macadamia genome preceded speciation of the genus Macadamia. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08174-0.
Collapse
Affiliation(s)
- Mohamed C M Zakeel
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, GPO Box 267, Brisbane, QLD, 4001, Australia.
| | - Andrew D W Geering
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, GPO Box 267, Brisbane, QLD, 4001, Australia
| | - John E Thomas
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, GPO Box 267, Brisbane, QLD, 4001, Australia
| | - Olufemi A Akinsanmi
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, GPO Box 267, Brisbane, QLD, 4001, Australia.
| |
Collapse
|
9
|
Aimone CD, Lavington E, Hoyer JS, Deppong DO, Mickelson-Young L, Jacobson A, Kennedy GG, Carbone I, Hanley-Bowdoin L, Duffy S. Population diversity of cassava mosaic begomoviruses increases over the course of serial vegetative propagation. J Gen Virol 2021; 102:001622. [PMID: 34310272 PMCID: PMC8491896 DOI: 10.1099/jgv.0.001622] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/05/2021] [Indexed: 01/06/2023] Open
Abstract
Cassava mosaic disease (CMD) represents a serious threat to cassava, a major root crop for more than 300 million Africans. CMD is caused by single-stranded DNA begomoviruses that evolve rapidly, making it challenging to develop durable disease resistance. In addition to the evolutionary forces of mutation, recombination and reassortment, factors such as climate, agriculture practices and the presence of DNA satellites may impact viral diversity. To gain insight into the factors that alter and shape viral diversity in planta, we used high-throughput sequencing to characterize the accumulation of nucleotide diversity after inoculation of infectious clones corresponding to African cassava mosaic virus (ACMV) and East African cassava mosaic Cameroon virus (EACMCV) in the susceptible cassava landrace Kibandameno. We found that vegetative propagation had a significant effect on viral nucleotide diversity, while temperature and a satellite DNA did not have measurable impacts in our study. EACMCV diversity increased linearly with the number of vegetative propagation passages, while ACMV diversity increased for a time and then decreased in later passages. We observed a substitution bias toward C→T and G→A for mutations in the viral genomes consistent with field isolates. Non-coding regions excluding the promoter regions of genes showed the highest levels of nucleotide diversity for each genome component. Changes in the 5' intergenic region of DNA-A resembled the sequence of the cognate DNA-B sequence. The majority of nucleotide changes in coding regions were non-synonymous, most with predicted deleterious effects on protein structure, indicative of relaxed selection pressure over six vegetative passages. Overall, these results underscore the importance of knowing how cropping practices affect viral evolution and disease progression.
Collapse
Affiliation(s)
- Catherine D. Aimone
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh NC 27695, USA
| | - Erik Lavington
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ 08901, USA
| | - J. Steen Hoyer
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ 08901, USA
| | - David O. Deppong
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh NC 27695, USA
| | - Leigh Mickelson-Young
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh NC 27695, USA
| | - Alana Jacobson
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - George G. Kennedy
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| | - Ignazio Carbone
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh NC 27695, USA
| | - Linda Hanley-Bowdoin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh NC 27695, USA
| | - Siobain Duffy
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ 08901, USA
| |
Collapse
|
10
|
Avalos-Calleros JA, Pastor-Palacios G, Bolaños-Martínez OC, Mauricio-Castillo A, Gregorio-Jorge J, Martínez-Marrero N, Bañuelos-Hernández B, Méndez-Lozano J, Arguello-Astorga GR. Two strains of a novel begomovirus encoding Rep proteins with identical β1 strands but different β5 strands are not compatible in replication. Arch Virol 2021; 166:1691-1709. [PMID: 33852083 DOI: 10.1007/s00705-021-05066-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 02/20/2021] [Indexed: 10/21/2022]
Abstract
Geminiviruses have genomes composed of single-stranded DNA molecules and encode a rolling-circle replication (RCR) initiation protein ("Rep"), which has multiple functions. Rep binds to specific repeated DNA motifs ("iterons"), which are major determinants of virus-specific replication. The particular amino acid (aa) residues that determine the preference of a geminivirus Rep for specific iterons (i.e., the trans-acting replication "specificity determinants", or SPDs) are largely unknown, but diverse lines of evidence indicate that most of them are closely associated with the so-called RCR motif I (FLTYP), located in the first 12-19 aa residues of the protein. In this work, we characterized two strains of a novel begomovirus, rhynchosia golden mosaic Sinaloa virus (RhGMSV), that were incompatible in replication in pseudorecombination experiments. Systematic comparisons of the Rep proteins of both RhGMSV strains in the DNA-binding domain allowed the aa residues at positions 71 and 74 to be identified as the residues most likely to be responsible for differences in replication specificity. Residue 71 is part of the β-5 strand structural element, which was predicted in previous studies to contain Rep SPDs. Since the Rep proteins encoded by both RhGMSV strains are identical in their first 24 aa residues, where other studies have mapped potential SPDs, this is the first study lending direct support to the notion that geminivirus Rep proteins contain separate SPDs in their N-terminal domain.
Collapse
Affiliation(s)
- Jesús Aarón Avalos-Calleros
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, A.C. Camino a la Presa de San José 2055, Lomas 4a Sección, C.P. 78216, San Luis Potosí, S.L.P., Mexico
| | - Guillermo Pastor-Palacios
- CONACYT-Consorcio de Investigación Innovación y Desarrollo para las Zonas Áridas, Instituto Potosino de Investigación Científica y Tecnológica, A.C. Camino a La Presa de San José 2055, Lomas 4a Sección, C.P. 78216, San Luis Potosí, S.L.P., Mexico
| | - Omayra C Bolaños-Martínez
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, A.C. Camino a la Presa de San José 2055, Lomas 4a Sección, C.P. 78216, San Luis Potosí, S.L.P., Mexico
| | | | - Josefat Gregorio-Jorge
- Consejo Nacional de Ciencia y Tecnología, Universidad Politécnica de Tlaxcala (UPTx)., Av. Insurgentes Sur 1582, Col. Crédito Constructor, Del. Benito Juárez, 03940, Mexico City, Mexico
| | - Nadia Martínez-Marrero
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, A.C. Camino a la Presa de San José 2055, Lomas 4a Sección, C.P. 78216, San Luis Potosí, S.L.P., Mexico
| | - Bernardo Bañuelos-Hernández
- Facultad de Agronomia y Veterinaria, Universidad De La Salle Bajio, Avenida Universidad 602, Lomas del Campestre, 37150, León Guanajuato, Mexico
| | - Jesús Méndez-Lozano
- Departamento de Biotecnología Agrícola, Instituto Politécnico Nacional, CIIDIR-Unidad Sinaloa, 81101, Guasave, Sinaloa, Mexico
| | - Gerardo Rafael Arguello-Astorga
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, A.C. Camino a la Presa de San José 2055, Lomas 4a Sección, C.P. 78216, San Luis Potosí, S.L.P., Mexico.
| |
Collapse
|
11
|
Shen W, Hanley-Bowdoin L. SnRK1: a versatile plant protein kinase that limits geminivirus infection. Curr Opin Virol 2020; 47:18-24. [PMID: 33360933 DOI: 10.1016/j.coviro.2020.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/22/2020] [Accepted: 12/03/2020] [Indexed: 01/08/2023]
Abstract
Geminiviruses are a family of single-stranded DNA viruses that infect many plant species and cause serious diseases in important crops. The plant protein kinase, SnRK1, has been implicated in host defenses against geminiviruses. Overexpression of SnRK1 makes plants more resistant to geminivirus infection, and knock-down of SnRK1 increases susceptibility to geminivirus infection. GRIK, the SnRK1 activating kinase, is upregulated by geminivirus infection, while the viral C2 protein inhibits the SnRK1 activity. SnRK1 also directly phosphorylates geminivirus proteins to reduce infection. These data suggest that SnRK1 is involved in the co-evolution of plant hosts and geminiviruses.
Collapse
Affiliation(s)
- Wei Shen
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA.
| | - Linda Hanley-Bowdoin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| |
Collapse
|
12
|
Bolatti EM, Zorec TM, Montani ME, Hošnjak L, Chouhy D, Viarengo G, Casal PE, Barquez RM, Poljak M, Giri AA. A Preliminary Study of the Virome of the South American Free-Tailed Bats ( Tadarida brasiliensis) and Identification of Two Novel Mammalian Viruses. Viruses 2020; 12:v12040422. [PMID: 32283670 PMCID: PMC7232368 DOI: 10.3390/v12040422] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022] Open
Abstract
Bats provide important ecosystem services as pollinators, seed dispersers, and/or insect controllers, but they have also been found harboring different viruses with zoonotic potential. Virome studies in bats distributed in Asia, Africa, Europe, and North America have increased dramatically over the past decade, whereas information on viruses infecting South American species is scarce. We explored the virome of Tadarida brasiliensis, an insectivorous New World bat species inhabiting a maternity colony in Rosario (Argentina), by a metagenomic approach. The analysis of five pooled oral/anal swab samples indicated the presence of 43 different taxonomic viral families infecting a wide range of hosts. By conventional nucleic acid detection techniques and/or bioinformatics approaches, the genomes of two novel viruses were completely covered clustering into the Papillomaviridae (Tadarida brasiliensis papillomavirus type 1, TbraPV1) and Genomoviridae (Tadarida brasiliensis gemykibivirus 1, TbGkyV1) families. TbraPV1 is the first papillomavirus type identified in this host and the prototype of a novel genus. TbGkyV1 is the first genomovirus reported in New World bats and constitutes a new species within the genus Gemykibivirus. Our findings extend the knowledge about oral/anal viromes of a South American bat species and contribute to understand the evolution and genetic diversity of the novel characterized viruses.
Collapse
Affiliation(s)
- Elisa M. Bolatti
- Grupo Virología Humana, Instituto de Biología Molecular y Celular de Rosario (CONICET), Suipacha 590, Rosario 2000, Argentina; (E.M.B.); (D.C.); (G.V.)
- Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina;
| | - Tomaž M. Zorec
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia; (T.M.Z.); (L.H.)
| | - María E. Montani
- Museo Provincial de Ciencias Naturales “Dr. Ángel Gallardo”, San Lorenzo 1949, Rosario 2000, Argentina;
- Programa de Conservación de los Murciélagos de Argentina, Miguel Lillo 251, San Miguel de Tucumán 4000, Argentina;
- Programa de Investigaciones de Biodiversidad Argentina, Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Miguel Lillo 205, San Miguel de Tucumán 4000, Argentina
| | - Lea Hošnjak
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia; (T.M.Z.); (L.H.)
| | - Diego Chouhy
- Grupo Virología Humana, Instituto de Biología Molecular y Celular de Rosario (CONICET), Suipacha 590, Rosario 2000, Argentina; (E.M.B.); (D.C.); (G.V.)
- Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina;
| | - Gastón Viarengo
- Grupo Virología Humana, Instituto de Biología Molecular y Celular de Rosario (CONICET), Suipacha 590, Rosario 2000, Argentina; (E.M.B.); (D.C.); (G.V.)
| | - Pablo E. Casal
- Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina;
| | - Rubén M. Barquez
- Programa de Conservación de los Murciélagos de Argentina, Miguel Lillo 251, San Miguel de Tucumán 4000, Argentina;
- Programa de Investigaciones de Biodiversidad Argentina, Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Miguel Lillo 205, San Miguel de Tucumán 4000, Argentina
| | - Mario Poljak
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia; (T.M.Z.); (L.H.)
- Correspondence: (M.P.); (A.A.G.); Tel.: +386-1-543-7454 (M.P.); +54-341-435-0661 (ext. 116) (A.A.G.); Fax: +54-341-439-0465 (A.A.G.)
| | - Adriana A. Giri
- Grupo Virología Humana, Instituto de Biología Molecular y Celular de Rosario (CONICET), Suipacha 590, Rosario 2000, Argentina; (E.M.B.); (D.C.); (G.V.)
- Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina;
- Correspondence: (M.P.); (A.A.G.); Tel.: +386-1-543-7454 (M.P.); +54-341-435-0661 (ext. 116) (A.A.G.); Fax: +54-341-439-0465 (A.A.G.)
| |
Collapse
|
13
|
Viral DNA genomes in sera of farrowing sows with or without stillbirths. PLoS One 2020; 15:e0230714. [PMID: 32214388 PMCID: PMC7098587 DOI: 10.1371/journal.pone.0230714] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 03/06/2020] [Indexed: 11/19/2022] Open
Abstract
A study was conducted to investigate the serum virome of sows with and without stillbirths after farrowing. Sera from sows with at least one stillbirth or with normal litters were collected immediately after farrowing. Viral DNA was extracted from serum pools and submitted to high throughput sequencing. No differences in the proportion of virus-related reads were found in both groups (p > 0.05). A variety of viral DNA genomes were identified, mostly representative of three viral families: Anelloviridae, Circoviridae and Smacoviridae. Besides, a number of novel unclassified circular Rep-encoding single stranded DNA (CRESS DNA) viruses were also identified. These findings suggest that the presence of such viral genomes in sows’ sera bears no correlation with stillbirths’ occurrence; it seems likely that these constitute part of the normal serum microbiome of sows at farrowing.
Collapse
|
14
|
Guerrero J, Sunter G. Complementary-sense gene regulation in beet curly top virus-SpCT. Arch Virol 2019; 164:2823-2828. [PMID: 31485748 DOI: 10.1007/s00705-019-04385-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/27/2019] [Indexed: 11/28/2022]
Abstract
A 278-bp region upstream of the beet curly top virus-SpCT (BCTV-SpCT) C2/C3 genes is necessary for promoter activity and exhibits significant sequence similarity to AL2/3 promoter sequences in tomato golden mosaic virus (TGMV). Maximal expression of the downstream C2/3 genes in BCTV-SpCT requires the presence of the C1 protein, which is supported by observations that mutation of the initiator codon for C1 results in decreased C2/C3 expression. This is similar to TGMV and cabbage leaf curl virus, where AL1 is required for maximal AL2/3 expression. Together, these data suggest a common strategy for complementary-sense gene regulation amongst curtoviruses and begomoviruses.
Collapse
Affiliation(s)
- Jennifer Guerrero
- Department of Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Garry Sunter
- Department of Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
| |
Collapse
|
15
|
Maio F, Arroyo-Mateos M, Bobay BG, Bejarano ER, Prins M, van den Burg HA. A Lysine Residue Essential for Geminivirus Replication Also Controls Nuclear Localization of the Tomato Yellow Leaf Curl Virus Rep Protein. J Virol 2019; 93:e01910-18. [PMID: 30842320 PMCID: PMC6498046 DOI: 10.1128/jvi.01910-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/20/2019] [Indexed: 02/07/2023] Open
Abstract
Geminiviruses are single-stranded DNA (ssDNA) viruses that infect a wide range of plants. To promote viral replication, geminiviruses manipulate the host cell cycle. The viral protein Rep is essential to reprogram the cell cycle and then initiate viral DNA replication by interacting with a plethora of nuclear host factors. Even though many protein domains of Rep have been characterized, little is known about its nuclear targeting. Here, we show that one conserved lysine in the N-terminal part of Rep is pivotal for nuclear localization of the Rep protein from Tomato yellow leaf curl virus (TYLCV), with two other lysines also contributing to its nuclear import. Previous work had identified that these residues are essential for Rep from Tomato golden mosaic virus (TGMV) to interact with the E2 SUMO-conjugating enzyme (SCE1). We here show that mutating these lysines leads to nuclear exclusion of TYLCV Rep without compromising its interaction with SCE1. Moreover, the ability of TYLCV Rep to promote viral DNA replication also depends on this highly conserved lysine independently of its role in nuclear import of Rep. Our data thus reveal that this lysine potentially has a broad role in geminivirus replication, but its role in nuclear import and SCE1 binding differs depending on the Rep protein examined.IMPORTANCE Nuclear activity of the replication initiator protein (Rep) of geminiviruses is essential for viral replication. We now define that one highly conserved lysine is important for nuclear import of Rep from three different begomoviruses. To our knowledge, this is the first time that nuclear localization has been mapped for any geminiviral Rep protein. Our data add another key function to this lysine residue, besides its roles in viral DNA replication and interaction with host factors, such as the SUMO E2-conjugating enzyme.
Collapse
Affiliation(s)
- Francesca Maio
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Manuel Arroyo-Mateos
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, Málaga, Spain
| | - Benjamin G Bobay
- Duke University NMR Center, Duke University Medical Center, Durham, North Carolina, USA
- Department of Biochemistry, Duke University, Durham, North Carolina, USA
- Department of Radiology, Duke University, Durham, North Carolina, USA
| | - Eduardo R Bejarano
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, Málaga, Spain
| | - Marcel Prins
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
- Keygene N.V., Wageningen, the Netherlands
| | - Harrold A van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| |
Collapse
|
16
|
Xu X, Qian Y, Wang Y, Li Z, Zhou X. Iterons Homologous to Helper Geminiviruses Are Essential for Efficient Replication of Betasatellites. J Virol 2019; 93:e01532-18. [PMID: 30541843 PMCID: PMC6384059 DOI: 10.1128/jvi.01532-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 11/28/2018] [Indexed: 11/20/2022] Open
Abstract
Betasatellites associated with geminiviruses can be replicated promiscuously by distinct geminiviruses but exhibit a preference for cognate helper viruses. However, the cis elements responsible for betasatellite origin recognition have not been characterized. In this study, we identified an iteron-like repeated sequence motif, 5'-GAGGACC-3', in a tobacco curly shoot betasatellite (TbCSB) associated with tobacco curly shoot virus (TbCSV). Competitive DNA binding assays revealed that two core repeats (5'-GGACC-3') are required for specific binding to TbCSV Rep; TbCSB iteron mutants accumulated to greatly reduced levels and lost the cognate helper-mediated replication preference. Interestingly, TbCSV also contains identical repeated sequences that are essential for specific Rep binding and in vivo replication. In order to gain insight into the mechanism by which TbCSB has acquired the cognate iterons, we performed a SELEX (systematic evolution of ligands by exponential enrichment) assay to identify the high-affinity Rep binding ligands from a large pool of randomized sequences. Analysis of SELEX winners showed that all of the sequences contained at least one core iteron-like motif, suggesting that TbCSB has evolved to contain cognate iterons for high-affinity Rep binding. Further analyses of various betasatellite sequences revealed a region upstream of the satellite conserved region replete with iterative sequence motifs, including species-specific repeats and a general repeat (5'-GGTAAAT-3'). Remarkably, the species-specific repeats in many betasatellites are homologous to those in their respective cognate helper begomoviruses, whereas the general repeat is widespread in most of the betasatellite molecules analyzed. These data, taken together, suggest that many betasatellites have evolved to acquire homologous iteron-like sequences for efficient replication mediated by cognate helper viruses.IMPORTANCE The geminivirus-encoded replication initiator protein (Rep) binds to repeated sequence elements (also known as iterons) in the origin of replication that serve as essential cis elements for specific viral replication. Betasatellites associated with begomoviruses can be replicated by cognate or noncognate helper viruses, but the cis elements responsible for betasatellite origin recognition have not been characterized. Using a betasatellite (TbCSB) associated with tobacco curly shoot virus (TbCSV) as a model, we identify two tandem repeats (iterons) in the Rep-binding motif (RBM) that are required for specific Rep binding and efficient replication, and we show that identical iteron sequences present in TbCSV are also necessary for Rep binding and the replication of helper viruses. Extensive analysis of begomovirus/betasatellite sequences shows that many betasatellites contain iteron-like elements homologous to those of their respective cognate helper begomoviruses. Our data suggest that many betasatellites have evolved to acquire homologous iteron-like sequences for efficient replication mediated by cognate helper viruses.
Collapse
Affiliation(s)
- Xiongbiao Xu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yajuan Qian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Zhenghe Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| |
Collapse
|
17
|
Hamza M, Tahir MN, Mustafa R, Kamal H, Khan MZ, Mansoor S, Briddon RW, Amin I. Identification of a dicot infecting mastrevirus along with alpha- and betasatellite associated with leaf curl disease of spinach (Spinacia oleracea) in Pakistan. Virus Res 2018; 256:174-182. [PMID: 30149045 DOI: 10.1016/j.virusres.2018.08.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/16/2018] [Accepted: 08/23/2018] [Indexed: 10/28/2022]
Abstract
Spinach is a common vegetable crop and very little data is available about its virus infection. Symptomatic leaves of spinach were collected during field survey. Circular DNA molecules were amplified from symptomatic samples using rolling circle amplification (RCA). After restriction analysis, presumed bands of virus and satellites were cloned, sequenced and analyzed. Analysis of sequenced RCA product revealed the presence of chickpea chlorotic dwarf virus (CpCDV; Mastrevirus). Further analyses of the cloned virus showed that strain "C" of CpCDV was present in symptomatic samples of spinach collected from field associated with vein darkening, curling and enations on leaves. Amplification of alpha- and betasatellites with universal primers was performed. CpCDV showed association with cotton leaf curl Multan betasatellite (CLCuMB) and cotton leaf curl Multan alphasatellites (CLCuMA). Infectivity analysis of CpCDV and CpCDV/CLCuMB were done in N. benthamiana using particle bombardment method and the results showed that CpCDV was able to transreplicates CLCuMB in this host. To our knowledge, this is the first report of a dicot infecting mastrevirus (CpCDV) along with CLCuMB and CLCuMA associated with leaf curl disease of spinach in Pakistan. The significance of the results is discussed.
Collapse
Affiliation(s)
- Muhammad Hamza
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan; Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Muhammad Nouman Tahir
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan; Department of Plant Pathology, Bahauddin Zakariya University, Multan, Pakistan
| | - Roma Mustafa
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan; Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Hira Kamal
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan; Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Muhammad Zuhaib Khan
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan
| | - Shahid Mansoor
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan
| | - Rob W Briddon
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan
| | - Imran Amin
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan.
| |
Collapse
|
18
|
Ruhel R, Chakraborty S. Multifunctional roles of geminivirus encoded replication initiator protein. Virusdisease 2018; 30:66-73. [PMID: 31143833 DOI: 10.1007/s13337-018-0458-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 05/28/2018] [Indexed: 12/31/2022] Open
Abstract
Geminivirus infection has been a threat to cultivation worldwide by causing huge losses to the crop. The single-stranded DNA genome of a geminivirus possesses a limited coding potential and many of the open reading frames (ORFs) are overlapping. Out of 5-7 ORFs that a geminivirus genome codes for, the AC1 ORF encodes for the replication initiator protein (Rep) which is involved in the replication of virus within the infected plant cell. Rep is the only viral protein absolutely required for the in planta viral replication. Across different genera of the Geminiviridae family, the AC1 ORF exhibits a high degree of sequence conservation thus it has been used as an effective target for developing broad spectrum resistance against the invading geminiviruses. This multifunctional protein is required for initiation, elongation as well as termination of the viral replication process. Rep is also involved in stimulation of viral transcription. In addition, it also functions as suppressor of gene silencing and is involved in the process of transcription by regulating the expression of certain viral genes. Rep protein also interacts with few viral proteins such as coat protein, replication enhancer protein and with several host factors involved in different pathways and processes for its replication and efficient infection. This review will summarise our current understanding about the role of this early viral protein in viral propagation as well as in establishment of pathogenesis in a permissive host.
Collapse
Affiliation(s)
- Rajrani Ruhel
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| |
Collapse
|
19
|
Varsani A, Krupovic M. Sequence-based taxonomic framework for the classification of uncultured single-stranded DNA viruses of the family Genomoviridae. Virus Evol 2017; 3:vew037. [PMID: 28458911 PMCID: PMC5399927 DOI: 10.1093/ve/vew037] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
With the advent of metagenomics approaches, a large diversity of known and unknown viruses has been identified in various types of environmental, plant, and animal samples. One such widespread virus group is the recently established family Genomoviridae which includes viruses with small (∼2-2.4 kb), circular ssDNA genomes encoding rolling-circle replication initiation proteins (Rep) and unique capsid proteins. Here, we propose a sequence-based taxonomic framework for classification of 121 new virus genomes within this family. Genomoviruses display ∼47% sequence diversity, which is very similar to that within the well-established and extensively studied family Geminiviridae (46% diversity). Based on our analysis, we establish a 78% genome-wide pairwise identity as a species demarcation threshold. Furthermore, using a Rep sequence phylogeny-based analysis coupled with the current knowledge on the classification of geminiviruses, we establish nine genera within the Genomoviridae family. These are Gemycircularvirus (n = 73), Gemyduguivirus (n = 1), Gemygorvirus (n = 9), Gemykibivirus (n = 29), Gemykolovirus (n = 3), Gemykrogvirus (n = 3), Gemykroznavirus (n = 1), Gemytondvirus (n = 1), Gemyvongvirus (n = 1). The presented taxonomic framework offers rational classification of genomoviruses based on the sequence information alone and sets an example for future classification of other groups of uncultured viruses discovered using metagenomics approaches.
Collapse
Affiliation(s)
- Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, School of Life sciences, Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85287, USA.,Structural Biology Research Unit, Department of Clinical Laboratory Sciences, University of Cape Town, Observatory 7700, South Africa
| | - Mart Krupovic
- Unité Biologie moléculaire du Gène chez les Extrêmophiles, Department of Microbiology, Institut Pasteur, 25 rue du Docteur Roux, Paris 75015, France
| |
Collapse
|
20
|
Kraberger S, Argüello-Astorga GR, Greenfield LG, Galilee C, Law D, Martin DP, Varsani A. Characterisation of a diverse range of circular replication-associated protein encoding DNA viruses recovered from a sewage treatment oxidation pond. INFECTION GENETICS AND EVOLUTION 2015; 31:73-86. [PMID: 25583447 DOI: 10.1016/j.meegid.2015.01.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 12/23/2014] [Accepted: 01/02/2015] [Indexed: 12/20/2022]
Abstract
Our knowledge of circular replication-associated protein encoding single-stranded (CRESS) DNA virus diversity has increased dramatically in recent years, largely due to advances in high-throughput sequencing technologies. These viruses are apparently major virome components in most terrestrial and aquatic environments and it is therefore of interest to determine their diversity at the interfaces between these environments. Treated sewage water is a particularly interesting interface between terrestrial and aquatic viromes in that it is directly pumped into waterways and is likely to contain virus populations that have been strongly impacted by humans. We used a combination of high-throughput sequencing, full genome PCR amplification, cloning and Sanger sequencing to investigate the diversity of CRESS DNA viruses present in a sewage oxidation pond. Using this approach, we recovered 50 putatively complete novel CRESS viral genomes (it remains possible that some are components of multipartite viral genomes) and 11 putatively sub-genome-length circular DNA molecules which may be either defective genomes or components of multipartite genomes. Thirteen of the genomes have bidirectional genome organisations and share similar conserved replication-associated protein (Rep) motifs to those of the gemycircularviruses: a group that in turn is most closely related to the geminiviruses. The remaining 37 viral genomes share very low degrees of Rep similarity to those of all other known CRESS DNA viruses. This number of highly divergent CRESS DNA virus genomes within a single sewage treatment pond further reinforces the notion that there likely exist hundreds of completely unknown genus/family level CRESS DNA virus groupings.
Collapse
Affiliation(s)
- Simona Kraberger
- School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Gerardo R Argüello-Astorga
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, 78216 San Luis Potosí, S.L.P., Mexico
| | - Laurence G Greenfield
- School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Craig Galilee
- School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Donald Law
- The Laboratories, Christchurch City Council, Christchurch, New Zealand
| | - Darren P Martin
- Computational Biology Group, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Arvind Varsani
- School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; Electron Microscope Unit, Division of Medical Biochemistry, Department of Clinical Laboratory Sciences, University of Cape Town, Rondebosch, 7701 Cape Town, South Africa; Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA; Biomolecular Interaction Centre, University of Canterbury, Christchurch 8140, New Zealand.
| |
Collapse
|
21
|
Bordeleau E, Ghinet MG, Burrus V. Diversity of integrating conjugative elements in actinobacteria: Coexistence of two mechanistically different DNA-translocation systems. Mob Genet Elements 2014; 2:119-124. [PMID: 22934248 PMCID: PMC3429521 DOI: 10.4161/mge.20498] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Conjugation is certainly the most widespread and promiscuous mechanism of horizontal gene transfer in bacteria. During conjugation, DNA translocation across membranes of two cells forming a mating pair is mediated by two types of mobile genetic elements: conjugative plasmids and integrating conjugative elements (ICEs). The vast majority of conjugative plasmids and ICEs employ a sophisticated protein secretion apparatus called type IV secretion system to transfer to a recipient cell. Yet another type of conjugative DNA translocation machinery exists and to date appears to be unique to conjugative plasmids and ICEs of the Actinomycetales order, a sub-group of high G + C Gram-positive bacteria. This conjugative system is reminiscent of the machinery that allows segregation of chromosomal DNA during bacterial cell division and sporulation, and relies on a single FtsK-homolog protein to translocate double-stranded DNA molecules to the recipient cell. Recent thorough sequence analyses reveal that while this latter strategy appears to be used by the majority of ICEs in Actinomycetales, the former is also predicted to be important in exchange of genetic material in actinobacteria.
Collapse
Affiliation(s)
- Eric Bordeleau
- Département de biologie; Faculté des sciences; Université de Sherbrooke; QC, Canada
| | | | | |
Collapse
|
22
|
Silva FN, Lima ATM, Rocha CS, Castillo-Urquiza GP, Alves-Júnior M, Zerbini FM. Recombination and pseudorecombination driving the evolution of the begomoviruses Tomato severe rugose virus (ToSRV) and Tomato rugose mosaic virus (ToRMV): two recombinant DNA-A components sharing the same DNA-B. Virol J 2014; 11:66. [PMID: 24708727 PMCID: PMC4113279 DOI: 10.1186/1743-422x-11-66] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 03/27/2014] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Begomoviruses are dicot-infecting, whitefly-transmitted viruses with a genome comprised of one or two molecules of circular, single-stranded DNA. In Brazil, tomato-infecting begomoviruses have emerged as serious pathogens since the introduction of a new biotype of the insect vector in the mid-1990's. Tomato rugose mosaic virus (ToRMV) and Tomato severe rugose virus (ToSRV) are often found in tomato fields. The complete sequence of the DNA-B components of ToSRV and ToRMV show an identity of 98.2%. Additionally, the high nucleotide identity (96.2%) between their common regions indicates that these two viruses may share the same DNA-B. METHODS Tomato seedlings were biolistically inoculated with ToSRV (DNA-A and DNA-B) and ToRMV (DNA-A and DNA-B) infectious clones in every possible combination of single or mixed infection. Symptom expression was evaluated for up to 35 days post-inoculation (dpi). DNA was extracted at 28 dpi and the presence of each viral genomic component was examined by rolling circle amplification (RCA) followed by digestion, as well as by quantitative, real-time PCR. Sequence comparisons, recombination and phylogenetic analyzes were performed using EMBOSS needle, RDP program and maximum likelihood inference, respectively. RESULTS Symptoms in tomato plants inoculated with the different combinations of ToRMV and ToSRV DNA-A and DNA-B components consisted of a typical mosaic in all combinations. Pseudorecombinants were formed in all possible combinations. When two DNA-A or two DNA-B components were inoculated simultaneously, the ToRMV components were detected preferentially in relation to the ToSRV components. The combination of minor changes in both the Rep protein and the CR may be involved in the preferential replication of ToRMV components. Recombination and phylogenetic analyzes support the exchange of genetic material between ToRMV and ToSRV. CONCLUSIONS ToRMV and ToSRV form viable pseudorecombinants in their natural host (Solanum lycopersicum) and share the same DNA-B. ToRMV DNA components are preferentially replicated over ToSRV components. These results indicate that the emergence of ToRMV involved both recombination and pseudorecombination, further highlighting the importance of these mechanisms in the emergence and adaptation of begomoviruses.
Collapse
Affiliation(s)
- Fábio N Silva
- Departamento de Fitopatologia/BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil
| | - Alison TM Lima
- Departamento de Fitopatologia/BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil
| | - Carolina S Rocha
- Current address: FuturaGene Brasil, Avenida José Lembo 1010, Itapeteninga, SP 18210-780, Brazil
| | | | - Miguel Alves-Júnior
- Current address: Faculdade de Ciências Agrárias, Universidade Federal do Pará, Altamira, PA 68372-040, Brazil
| | - F Murilo Zerbini
- Departamento de Fitopatologia/BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil
| |
Collapse
|
23
|
Hull R. Replication of Plant Viruses. PLANT VIROLOGY 2014. [PMCID: PMC7184227 DOI: 10.1016/b978-0-12-384871-0.00007-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Viruses replicate using both their own genetic information and host cell components and machinery. The different genome types have different replication pathways which contain controls on linking the process with translation and movement around the cell as well as not compromising the infected cell. This chapter discusses the replication mechanisms, faults in replication and replication of viruses co-infecting cells. Viruses replicate using both their own genetic information and host cell components and machinery. The different genome types have different replication pathways which contain controls on linking the process with translation and movement around the cell as well as not compromising the infected cell. This chapter discusses the replication mechanisms, faults in replication and replication of viruses coinfecting cells.
Collapse
|
24
|
Characterization of a complete genome of a circular single-stranded DNA virus from porcine stools in Korea. Virus Genes 2013; 48:81-8. [PMID: 24170425 DOI: 10.1007/s11262-013-1003-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 10/18/2013] [Indexed: 01/30/2023]
Abstract
Porcine circular single-stranded DNA viruses have been just identified from swine feces in Korea. This virus was mentioned as bovine stool-associated circular DNA virus (BoSCV)-like virus discovered from porcine stools. However, the thorough characteristics of the virus were not identified. Therefore, this research focuses on finding a full genome sequence and analyzing the genetic features of the virus. The virus, now called porcine stool-associated circular DNA virus in Korea (PoSCV Kor), consists of 2,589 bases forming circular structure. It has two major ORFs inversely encoding replicase and capsid protein, with each stem-loop structure between 5' ends and 3' ends of the two putative ORFs. This characteristics is the same as PoSCV in New Zealand, but different from chimpanzee stool-associated circular virus (ChiSCVs) and BoSCV, which have one stem-loop structure. Therefore, it would be sure that PoSCV Kor is very similar to PoSCV in respect to the genetic aspect; the same number of nucleotide bases and the amino acid identity of replicase and capsid protein (96 and 93 %, respectively). This fact could be certified through the finding that PoSCV Kor and PoSCV are in the same cluster by phylogenetic analysis based on the comparison with full-sequences of other circular ssDNA viruses.
Collapse
|
25
|
Reyes MI, Nash TE, Dallas MM, Ascencio-Ibáñez JT, Hanley-Bowdoin L. Peptide aptamers that bind to geminivirus replication proteins confer a resistance phenotype to tomato yellow leaf curl virus and tomato mottle virus infection in tomato. J Virol 2013; 87:9691-706. [PMID: 23824791 PMCID: PMC3754110 DOI: 10.1128/jvi.01095-13] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 06/21/2013] [Indexed: 01/17/2023] Open
Abstract
Geminiviruses constitute a large family of single-stranded DNA viruses that cause serious losses in important crops worldwide. They often exist in disease complexes and have high recombination and mutation rates, allowing them to adapt rapidly to new hosts and environments. Thus, an effective resistance strategy must be general in character and able to target multiple viruses. The geminivirus replication protein (Rep) is a good target for broad-based disease control because it is highly conserved and required for viral replication. In an earlier study, we identified a set of peptide aptamers that bind to Rep and reduce viral replication in cultured plant cells. In this study, we selected 16 of the peptide aptamers for further analysis in yeast two-hybrid assays. The results of these experiments showed that all 16 peptide aptamers interact with all or most of the Rep proteins from nine viruses representing the three major Geminiviridae genera and identified two peptide aptamers (A22 and A64) that interact strongly with different regions in the Rep N terminus. Transgenic tomato lines expressing A22 or A64 and inoculated with Tomato yellow leaf curl virus or Tomato mottle virus exhibited delayed viral DNA accumulation and often contained lower levels of viral DNA. Strikingly, the effect on symptoms was stronger, with many of the plants showing no symptoms or strongly attenuated symptoms. Together, these results established the efficacy of using Rep-binding peptide aptamers to develop crops that are resistant to diverse geminiviruses.
Collapse
Affiliation(s)
- Maria Ines Reyes
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina, USA
| | | | | | | | | |
Collapse
|
26
|
Abstract
Geminiviruses are a family of plant viruses that cause economically important plant diseases worldwide. These viruses have circular single-stranded DNA genomes and four to eight genes that are expressed from both strands of the double-stranded DNA replicative intermediate. The transcription of these genes occurs under the control of two bidirectional promoters and one monodirectional promoter. The viral proteins function to facilitate virus replication, virus movement, the assembly of virus-specific nucleoprotein particles, vector transmission and to counteract plant host defence responses. Recent research findings have provided new insights into the structure and function of these proteins and have identified numerous host interacting partners. Most of the viral proteins have been shown to be multifunctional, participating in multiple events during the infection cycle and have, indeed, evolved coordinated interactions with host proteins to ensure a successful infection. Here, an up-to-date review of viral protein structure and function is presented, and some areas requiring further research are identified.
Collapse
Affiliation(s)
- Vincent N Fondong
- Department of Biological Sciences, Delaware State University, 1200 North DuPont Highway, Dover, DE 19901, USA.
| |
Collapse
|
27
|
Coco D, Calil IP, Brustolini OJB, Santos AA, Inoue-Nagata AK, Fontes EPB. Soybean chlorotic spot virus, a novel begomovirus infecting soybean in Brazil. Arch Virol 2013; 158:457-62. [PMID: 23053525 DOI: 10.1007/s00705-012-1499-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 08/25/2012] [Indexed: 11/27/2022]
Abstract
A novel soybean-infecting begomovirus from Brazil was identified in Jaíba, in the state of Minas Gerais, and molecularly characterized. By using rolling-circle amplification-based cloning of viral DNAs, three DNA-A variants and a cognate DNA-B were isolated from infected samples. The DNA variants share more than 98 % sequence identity but have less than 89 % identity to other reported begomovirus, the limit for demarcation of new species. In a phylogenetic analysis, both DNA-A and DNA-B clustered with other Brazilian begomoviruses. Infectious cloned DNA-A and DNA-B components induced distinct symptoms in Solanaceae and Fabaceae species by biolistic inoculation. In soybean, the virus induced mild symptoms, i.e., chlorotic spots on the leaves, from which the name soybean chlorotic spot virus (SoCSV) was proposed. The most severe symptoms were displayed by common beans, which exhibited leaf distortion, blistering, interveinal chlorosis, mosaic and golden mosaic. The possibility that SoCSV may become a threat to bean production in Brazil is discussed.
Collapse
Affiliation(s)
- Daniela Coco
- Departamento de Bioquimica e Biologia Molecular, Universidade Federal de Vicosa, Vicosa, Brazil
| | | | | | | | | | | |
Collapse
|
28
|
Differential distribution and occurrence of simple sequence repeats in diverse geminivirus genomes. Virus Genes 2012; 45:556-66. [DOI: 10.1007/s11262-012-0802-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 07/31/2012] [Indexed: 01/13/2023]
|
29
|
Complete nucleotide sequence of watermelon chlorotic stunt virus originating from Oman. Viruses 2012; 4:1169-81. [PMID: 22852046 PMCID: PMC3407900 DOI: 10.3390/v4071169] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/06/2012] [Accepted: 07/20/2012] [Indexed: 11/24/2022] Open
Abstract
Watermelon chlorotic stunt virus (WmCSV) is a bipartite begomovirus (genus Begomovirus, family Geminiviridae) that causes economic losses to cucurbits, particularly watermelon, across the Middle East and North Africa. Recently squash (Cucurbita moschata) grown in an experimental field in Oman was found to display symptoms such as leaf curling, yellowing and stunting, typical of a begomovirus infection. Sequence analysis of the virus isolated from squash showed 97.6–99.9% nucleotide sequence identity to previously described WmCSV isolates for the DNA A component and 93–98% identity for the DNA B component. Agrobacterium-mediated inoculation to Nicotiana benthamiana resulted in the development of symptoms fifteen days post inoculation. This is the first bipartite begomovirus identified in Oman. Overall the Oman isolate showed the highest levels of sequence identity to a WmCSV isolate originating from Iran, which was confirmed by phylogenetic analysis. This suggests that WmCSV present in Oman has been introduced from Iran. The significance of this finding is discussed.
Collapse
|
30
|
Inhibition of Binding of Tomato Yellow Leaf Curl Virus Rep to its Replication Origin by Artificial Zinc-Finger Protein. Mol Biotechnol 2012; 54:198-203. [DOI: 10.1007/s12033-012-9552-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
31
|
Wyant PS, Strohmeier S, Schäfer B, Krenz B, Assunção IP, Lima GSDA, Jeske H. Circular DNA genomics (circomics) exemplified for geminiviruses in bean crops and weeds of northeastern Brazil. Virology 2012; 427:151-7. [PMID: 22397740 DOI: 10.1016/j.virol.2012.02.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/18/2012] [Accepted: 02/09/2012] [Indexed: 11/30/2022]
Abstract
Circomics was coined to describe the combination of rolling circle amplification (RCA), restriction fragment length polymorphism (RFLP) and pyro-sequencing to investigate the genome structures of small circular DNAs. A batch procedure is described using 61 plant samples from Asia, South America and Central America which revealed 83 contig sequences of geminiviral DNA components and 4 contig sequences of DNA satellites. The usefulness of this approach is validated for the Brazilian begomoviruses, and the sequence fidelity is determined by comparing the results with those of conventional cloning and sequencing of Bolivian begomoviruses reported recently. Therefore, circomics has been proven to be a major step forward to economize costs and labor and to characterize reliably geminiviral genomes in their population structure of the quasispecies.
Collapse
Affiliation(s)
- Patricia Soares Wyant
- Institute of Biology, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | | | | | | | | | | | | |
Collapse
|
32
|
Bruce G, Gu M, Shi N, Liu Y, Hong Y. Influence of retinoblastoma-related gene silencing on the initiation of DNA replication by African cassava mosaic virus Rep in cells of mature leaves in Nicotiana benthamiana plants. Virol J 2011; 8:561. [PMID: 22204717 PMCID: PMC3286440 DOI: 10.1186/1743-422x-8-561] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 12/28/2011] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Geminiviruses mainly infect terminally differentiated tissues and cells in plants. They need to reprogramme host cellular machinery for DNA replication. This process is thought to be mediated by inactivation of cell-cycle repressor proteins and by induction of host DNA synthesis protein expression through actions of the geminviral replication initiator protein (Rep). FINDINGS Exploiting a Nicotiana benthamiana pOri2 line, which is transformed with a transgene consisting of a direct repeat of the African cassava mosaic virus (ACMV)-replication origin (Ori) flanking a non-viral DNA region, and virus-induced RNA silencing (VIGS), the impact of host gene expression on replication of the ACMV-derived replicon was investigated. The ACMV Rep trans-replicated the viral episomal replicon in leaves of young but not older pOri2 plants. Upon VIGS-mediated down-regulation of N. benthamiana NbRBR1, the retinoblastoma-related protein gene coding for a negative cell-cycle suppressor, recovered the ability of ACMV Rep for trans DNA replication, whereas the silencing of NbPCNA coding for the sliding clamp of DNA polymerase had no effect. CONCLUSIONS These results suggest that the cellular machinery for DNA replication in differentiated tissues of older leaves cannot be reprogrammed by Rep alone but may need other uncharacterised viral and plant factors.
Collapse
Affiliation(s)
- Gareth Bruce
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
- Biological Sciences Research Unit, University of Glamorgan, Pontypridd, CF37 1DL Wales, UK
| | - Mei Gu
- Clinical Sciences Research Institute, University of Warwick, Coventry CV2 2DX, UK
| | - Nongnong Shi
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Yule Liu
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yiguo Hong
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| |
Collapse
|
33
|
Ghinet MG, Bordeleau E, Beaudin J, Brzezinski R, Roy S, Burrus V. Uncovering the prevalence and diversity of integrating conjugative elements in actinobacteria. PLoS One 2011; 6:e27846. [PMID: 22114709 PMCID: PMC3218068 DOI: 10.1371/journal.pone.0027846] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 10/26/2011] [Indexed: 12/01/2022] Open
Abstract
Horizontal gene transfer greatly facilitates rapid genetic adaptation of bacteria to shifts in environmental conditions and colonization of new niches by allowing one-step acquisition of novel functions. Conjugation is a major mechanism of horizontal gene transfer mediated by conjugative plasmids and integrating conjugative elements (ICEs). While in most bacterial conjugative systems DNA translocation requires the assembly of a complex type IV secretion system (T4SS), in Actinobacteria a single DNA FtsK/SpoIIIE-like translocation protein is required. To date, the role and diversity of ICEs in Actinobacteria have received little attention. Putative ICEs were searched for in 275 genomes of Actinobacteria using HMM-profiles of proteins involved in ICE maintenance and transfer. These exhaustive analyses revealed 144 putative FtsK/SpoIIIE-type ICEs and 17 putative T4SS-type ICEs. Grouping of the ICEs based on the phylogenetic analyses of maintenance and transfer proteins revealed extensive exchanges between different sub-families of ICEs. 17 ICEs were found in Actinobacteria from the genus Frankia, globally important nitrogen-fixing microorganisms that establish root nodule symbioses with actinorhizal plants. Structural analysis of ICEs from Frankia revealed their unexpected diversity and a vast array of predicted adaptive functions. Frankia ICEs were found to excise by site-specific recombination from their host's chromosome in vitro and in planta suggesting that they are functional mobile elements whether Frankiae live as soil saprophytes or plant endosymbionts. Phylogenetic analyses of proteins involved in ICEs maintenance and transfer suggests that active exchange between ICEs cargo-borne and chromosomal genes took place within the Actinomycetales order. Functionality of Frankia ICEs in vitro as well as in planta lets us anticipate that conjugation and ICEs could allow the development of genetic manipulation tools for this challenging microorganism and for many other Actinobacteria.
Collapse
Affiliation(s)
- Mariana Gabriela Ghinet
- Centre d'étude et de valorisation de la diversité microbienne, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Eric Bordeleau
- Centre d'étude et de valorisation de la diversité microbienne, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Julie Beaudin
- Centre d'étude et de valorisation de la diversité microbienne, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Ryszard Brzezinski
- Centre d'étude et de valorisation de la diversité microbienne, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Sébastien Roy
- Centre d'étude et de valorisation de la diversité microbienne, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
- * E-mail: (SR); (VB)
| | - Vincent Burrus
- Centre d'étude et de valorisation de la diversité microbienne, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
- * E-mail: (SR); (VB)
| |
Collapse
|
34
|
Sánchez-Durán MA, Dallas MB, Ascencio-Ibañez JT, Reyes MI, Arroyo-Mateos M, Ruiz-Albert J, Hanley-Bowdoin L, Bejarano ER. Interaction between geminivirus replication protein and the SUMO-conjugating enzyme is required for viral infection. J Virol 2011; 85:9789-800. [PMID: 21775461 PMCID: PMC3196459 DOI: 10.1128/jvi.02566-10] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 07/08/2011] [Indexed: 12/11/2022] Open
Abstract
Geminiviruses are small DNA viruses that replicate in nuclei of infected plant cells by using plant DNA polymerases. These viruses encode a protein designated AL1, Rep, or AC1 that is essential for viral replication. AL1 is an oligomeric protein that binds to double-stranded DNA, catalyzes the cleavage and ligation of single-stranded DNA, and induces the accumulation of host replication machinery. It also interacts with several host proteins, including the cell cycle regulator retinoblastoma-related protein (RBR), the DNA replication protein PCNA (proliferating cellular nuclear antigen), and the sumoylation enzyme that conjugates SUMO to target proteins (SUMO-conjugating enzyme [SCE1]). The SCE1-binding motif was mapped by deletion to a region encompassing AL1 amino acids 85 to 114. Alanine mutagenesis of lysine residues in the binding region either reduced or eliminated the interaction with SCE1, but no defects were observed for other AL1 functions, such as oligomerization, DNA binding, DNA cleavage, and interaction with AL3 or RBR. The lysine mutations reduced or abolished virus infectivity in plants and viral DNA accumulation in transient-replication assays, suggesting that the AL1-SCE1 interaction is required for viral DNA replication. Ectopic AL1 expression did not result in broad changes in the sumoylation pattern of plant cells, but specific changes were detected, indicating that AL1 modifies the sumoylation state of selected host proteins. These results established the importance of AL1-SCE1 interactions during geminivirus infection of plants and suggested that AL1 alters the sumoylation of selected host factors to create an environment suitable for viral infection.
Collapse
Affiliation(s)
- Miguel A. Sánchez-Durán
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departmento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Mary B. Dallas
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622
| | - José T. Ascencio-Ibañez
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622
| | - Maria Ines Reyes
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622
| | - Manuel Arroyo-Mateos
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departmento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Javier Ruiz-Albert
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departmento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Linda Hanley-Bowdoin
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622
| | - Eduardo R. Bejarano
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departmento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| |
Collapse
|
35
|
Martin DP, Biagini P, Lefeuvre P, Golden M, Roumagnac P, Varsani A. Recombination in eukaryotic single stranded DNA viruses. Viruses 2011; 3:1699-738. [PMID: 21994803 PMCID: PMC3187698 DOI: 10.3390/v3091699] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 08/18/2011] [Accepted: 09/05/2011] [Indexed: 12/23/2022] Open
Abstract
Although single stranded (ss) DNA viruses that infect humans and their domesticated animals do not generally cause major diseases, the arthropod borne ssDNA viruses of plants do, and as a result seriously constrain food production in most temperate regions of the world. Besides the well known plant and animal-infecting ssDNA viruses, it has recently become apparent through metagenomic surveys of ssDNA molecules that there also exist large numbers of other diverse ssDNA viruses within almost all terrestrial and aquatic environments. The host ranges of these viruses probably span the tree of life and they are likely to be important components of global ecosystems. Various lines of evidence suggest that a pivotal evolutionary process during the generation of this global ssDNA virus diversity has probably been genetic recombination. High rates of homologous recombination, non-homologous recombination and genome component reassortment are known to occur within and between various different ssDNA virus species and we look here at the various roles that these different types of recombination may play, both in the day-to-day biology, and in the longer term evolution, of these viruses. We specifically focus on the ecological, biochemical and selective factors underlying patterns of genetic exchange detectable amongst the ssDNA viruses and discuss how these should all be considered when assessing the adaptive value of recombination during ssDNA virus evolution.
Collapse
Affiliation(s)
- Darren P. Martin
- Computational Biology Group, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 4579, South Africa; E-Mail:
| | - Philippe Biagini
- UMR CNRS 6578 Anthropologie Bioculturelle, Equipe “Emergence et co-évolution virale”, Etablissement Français du Sang Alpes-Méditerranée, Université de la Méditerranée, 27 Bd. Jean Moulin, 13005 Marseille, France; E-Mail:
| | - Pierre Lefeuvre
- CIRAD, UMR 53 PVBMT CIRAD-Université de la Réunion, Pôle de Protection des Plantes, Ligne Paradis, 97410, Saint Pierre, La Réunion, France; E-Mail:
| | - Michael Golden
- Computational Biology Group, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 4579, South Africa; E-Mail:
| | - Philippe Roumagnac
- CIRAD, UMR BGPI, TA A-54/K, Campus International de Montferrier-Baillarguet, 34398 Montpellier, France; E-Mail:
| | - Arvind Varsani
- Electron Microscope Unit, University of Cape Town, Rondebosch, Cape Town 7701, South Africa; E-Mail:
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| |
Collapse
|
36
|
Nash TE, Dallas MB, Reyes MI, Buhrman GK, Ascencio-Ibañez JT, Hanley-Bowdoin L. Functional analysis of a novel motif conserved across geminivirus Rep proteins. J Virol 2011; 85:1182-92. [PMID: 21084480 PMCID: PMC3020519 DOI: 10.1128/jvi.02143-10] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 11/09/2010] [Indexed: 12/28/2022] Open
Abstract
Members of the Geminiviridae have single-stranded DNA genomes that replicate in nuclei of infected plant cells. All geminiviruses encode a conserved protein (Rep) that catalyzes initiation of rolling-circle replication. Earlier studies showed that three conserved motifs-motifs I, II, and III-in the N termini of geminivirus Rep proteins are essential for function. In this study, we identified a fourth sequence, designated GRS (geminivirus Rep sequence), in the Rep N terminus that displays high amino acid sequence conservation across all geminivirus genera. Using the Rep protein of Tomato golden mosaic virus (TGMV AL1), we show that GRS mutants are not infectious in plants and do not support viral genome replication in tobacco protoplasts. GRS mutants are competent for protein-protein interactions and for both double- and single-stranded DNA binding, indicating that the mutations did not impair its global conformation. In contrast, GRS mutants are unable to specifically cleave single-stranded DNA, which is required to initiate rolling-circle replication. Interestingly, the Rep proteins of phytoplasmal and algal plasmids also contain GRS-related sequences. Modeling of the TGMV AL1 N terminus suggested that GRS mutations alter the relative positioning of motif II, which coordinates metal ions, and motif III, which contains the tyrosine involved in DNA cleavage. Together, these results established that the GRS is a conserved, essential motif characteristic of an ancient lineage of rolling-circle initiators and support the idea that geminiviruses may have evolved from plasmids associated with phytoplasma or algae.
Collapse
Affiliation(s)
- Tara E. Nash
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7688
| | - Mary B. Dallas
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7688
| | - Maria Ines Reyes
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7688
| | - Gregory K. Buhrman
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7688
| | - J. Trinidad Ascencio-Ibañez
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7688
| | - Linda Hanley-Bowdoin
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7688
| |
Collapse
|
37
|
Cocca E, De Iorio S, Capriglione T. Identification of a novel helitron transposon in the genome of Antarctic fish. Mol Phylogenet Evol 2011; 58:439-46. [PMID: 21241813 DOI: 10.1016/j.ympev.2010.12.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 12/13/2010] [Accepted: 12/23/2010] [Indexed: 01/18/2023]
Abstract
Rolling-circle (RC) eukaryotic transposons, known as helitrons, are found in a wide range of organisms, from protist to mammals. Autonomous helitrons have a distinctive open reading frame (ORF) encoding a polypeptide that contains typical domains for RC replication (RCR): the Rep (RCR initiator) and the DNA helicase domains. These elements are believed to have an important role in the host genome evolution, owing to their frequent capture of host genes, some of which can evolve into novel genes or become essential for helitron transposition. We conducted a molecular analysis of the suborder Notothenioidei, a group of Perciformes that currently dominate the Antarctic waters by virtue of their remarkable cold-adaptation ability. A novel helitron from the genome of the icefish species Chionodraco hamatus, belonging to the Channichthyidae, the most derived Notothenioids family, was isolated, characterized and designated as HeliNoto (8.9 kb). Its ORF was compared to homologous sequences from different species in a comprehensive phylogenetic analysis. For the first time the putative functional domains of a helitron were subjected to a well accurate structural analysis including chromosomal localization. Finally, the distribution of HeliNoto among Notothenioids was investigated.
Collapse
Affiliation(s)
- Ennio Cocca
- Institute of Protein Biochemistry, National Research Council (CNR), Naples, Italy.
| | | | | |
Collapse
|
38
|
Abstract
The replication-associated protein (Rep) of geminiviruses, single-stranded DNA viruses of higher plants, is essential for virus replication. Since these viruses do not encode their own polymerases, Rep induces differentiated plant cells to reenter the cell cycle by interacting with the plant homologues of retinoblastoma proteins in order to activate the host DNA synthesis machinery. We have used fission yeast (Schizosaccharomyces pombe) as a model organism to analyze the impact of ectopically expressed African cassava mosaic virus Rep protein on the cell division cycle in closer detail. Upon expression, Rep showed its characteristic DNA cleavage activity, and about 10% of the cells exhibited morphological changes. They were elongated threefold, on average, and possessed a single but enlarged and less compact nucleus in comparison to noninduced or vector-only control cells. Flow cytometry of Rep-expressing cultures revealed a distinct subpopulation of Rep protein-containing cells with aberrant morphology. The other 90% of the cells were indistinguishable from control cells, and no Rep was detectable. Rep-expressing cells exhibited DNA contents beyond 2C, indicating ongoing replication without intervening mitosis. Because a second open reading frame (ORF), AC4, is present within the Rep gene, the role of AC4 was examined by destroying its start codon within the AC1 ORF. The results confirmed that Rep is necessary and sufficient to induce rereplication in fission yeast. The unique potential of this well-investigated model for dissecting the cell cycle control by geminiviral proteins is discussed.
Collapse
|
39
|
Abstract
Plant pathogenic geminiviruses have been proliferating worldwide and have, therefore, attracted considerable scientific interest during the past three decades. Current knowledge concerning their virion and genome structure, their molecular biology of replication, recombination, transcription, and silencing, as well as their transport through plants and dynamic competition with host responses are summarized. The topics are chosen to provide a comprehensive introduction for animal virologists, emphasizing similarities and differences to the closest functional relatives, polyomaviruses and circoviruses.
Collapse
|
40
|
Jin M, Li C, Shi Y, Ryabov E, Huang J, Wu Z, Fan Z, Hong Y. A single amino acid change in a geminiviral Rep protein differentiates between triggering a plant defence response and initiating viral DNA replication. J Gen Virol 2008; 89:2636-2641. [PMID: 18796734 DOI: 10.1099/vir.0.2008/001966-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have devised an in planta system for functional analysis of the replication-associated protein (Rep) of African cassava mosaic virus (ACMV). Using this assay and PCR-based random mutagenesis, we have identified an ACMV Rep mutant that failed to trigger the hypersensitive response (HR), but had an enhanced ability to initiate DNA replication. The mutant Rep-green fluorescent protein (GFP) fusion protein was localized to the nucleus. Sequence analysis showed that the mutated Rep gene had three nucleotide changes (A6-->T, T375-->G and G852-->A); only the A6-->T transversion resulted in an amino acid substitution (Arg to Ser), which is at the second residue in the 358 amino acid ACMV Rep protein. Our results indicate that a single amino acid can alter the differential ability of ACMV Rep to trigger the host-mediated HR defence mechanism and to initiate viral DNA replication. The implications of this finding are discussed in the context of plant-virus interactions.
Collapse
Affiliation(s)
- Mingfei Jin
- School of Life Science, East China Normal University, Shanghai 200062, PR China.,Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Chunyang Li
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Yan Shi
- Department of Plant Pathology and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100094, PR China.,Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Eugene Ryabov
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Jing Huang
- School of Life Science, East China Normal University, Shanghai 200062, PR China
| | - Zirong Wu
- School of Life Science, East China Normal University, Shanghai 200062, PR China
| | - Zaifeng Fan
- Department of Plant Pathology and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100094, PR China.,Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Yiguo Hong
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| |
Collapse
|
41
|
Kapitonov VV, Jurka J. Helitrons on a roll: eukaryotic rolling-circle transposons. Trends Genet 2007; 23:521-9. [PMID: 17850916 DOI: 10.1016/j.tig.2007.08.004] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2007] [Revised: 07/17/2007] [Accepted: 08/30/2007] [Indexed: 10/22/2022]
Abstract
Rolling-circle eukaryotic transposons, known as Helitron transposons, were first discovered in plants (Arabidopsis thaliana and Oryza sativa) and in the nematode Caenorhabditis elegans. To date, Helitrons have been identified in a diverse range of species, from protists to mammals. They represent a major class of eukaryotic transposons and are fundamentally different from classical transposons in terms of their structure and mechanism of transposition. Helitrons seem to have a major role in the evolution of host genomes. They frequently capture diverse host genes, some of which can evolve into novel host genes or become essential for helitron transposition.
Collapse
Affiliation(s)
- Vladimir V Kapitonov
- Genetic Information Research Institute, 1925 Landings Drive, Mountain View, CA 94043, USA.
| | | |
Collapse
|
42
|
Arguello-Astorga G, Ascencio-Ibáñez JT, Dallas MB, Orozco BM, Hanley-Bowdoin L. High-frequency reversion of geminivirus replication protein mutants during infection. J Virol 2007; 81:11005-15. [PMID: 17670823 PMCID: PMC2045516 DOI: 10.1128/jvi.00925-07] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The geminivirus replication protein AL1 interacts with retinoblastoma-related protein (RBR), a key regulator of the plant division cell cycle, to induce conditions permissive for viral DNA replication. Previous studies of tomato golden mosaic virus (TGMV) AL1 showed that amino acid L148 in the conserved helix 4 motif is critical for RBR binding. In this work, we examined the effect of an L148V mutation on TGMV replication in tobacco cells and during infection of Nicotiana benthamiana plants. The L148V mutant replicated 100 times less efficiently than wild-type TGMV in protoplasts but produced severe symptoms that were delayed compared to those of wild-type infection in plants. Analysis of progeny viruses revealed that the L148V mutation reverted at 100% frequency in planta to methionine, leucine, isoleucine, or a second-site mutation depending on the valine codon in the initial DNA sequence. Similar results were seen with another geminivirus, cabbage leaf curl virus (CaLCuV), carrying an L145A mutation in the equivalent residue. Valine was the predominant amino acid recovered from N. benthamiana plants inoculated with the CaLCuV L145A mutant, while threonine was the major residue in Arabidopsis thaliana plants. Together, these data demonstrated that there is strong selection for reversion of the TGMV L148V and CaLCuV L145A mutations but that the nature of the selected revertants is influenced by both the viral background and host components. These data also suggested that high mutation rates contribute to the rapid evolution of geminivirus genomes in plants.
Collapse
Affiliation(s)
- Gerardo Arguello-Astorga
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA
| | | | | | | | | |
Collapse
|
43
|
Shung CY, Sunter G. AL1-dependent repression of transcription enhances expression of Tomato golden mosaic virus AL2 and AL3. Virology 2007; 364:112-22. [PMID: 17407785 PMCID: PMC2902176 DOI: 10.1016/j.virol.2007.03.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 01/03/2007] [Accepted: 03/01/2007] [Indexed: 11/22/2022]
Abstract
Studies using Nicotiana benthamiana protoplasts have determined that repression of upstream transcription by AL1 protein enhances AL2 and AL3 expression in Tomato golden mosaic virus (TGMV). Mutations resulting in the inability of TGMV AL1 protein to associate with its cognate binding site, result in a decrease in both AL2 and AL3 expression. Reduced expression correlates with an increase in transcription from the AL62 start site, and decreased transcription from downstream initiation sites (AL1935 and AL1629) present within the AL1 coding region. The results demonstrate that, in a tobacco protoplast system, repression of AL62 transcription, regulated through binding of AL1 protein to sequences in the origin of replication, is required prior to AL2 and AL3 gene expression from the AL1935 and AL1629 viral transcripts. This provides a mechanism to regulate expression of AL2, which is involved in suppression of host defense responses and is required for late gene expression.
Collapse
Affiliation(s)
- Chia-Yi Shung
- Department of Biology The University of Texas at San Antonio One UTSA Circle San Antonio, TX 78249 USA
| | - Garry Sunter
- Department of Biology The University of Texas at San Antonio One UTSA Circle San Antonio, TX 78249 USA
| |
Collapse
|
44
|
Chilakamarthi U, Mukherjee SK, Deb JK. Intervention of geminiviral replication in yeast by ribozyme mediated downregulation of its Rep protein. FEBS Lett 2007; 581:2675-83. [PMID: 17531225 DOI: 10.1016/j.febslet.2007.04.084] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 04/20/2007] [Accepted: 04/25/2007] [Indexed: 11/29/2022]
Abstract
Geminiviruses pose serious threat to many economically important crops such as mungbean, tomato, cotton, etc. To devise a specific antiviral strategy at the viral DNA replication level, a hammerhead ribozyme was directed against the mRNA of the replication initiator protein (Rep). Rep is the most important viral protein for the DNA replication of the Mungbean yellow mosaic India virus (MYMIV), a member of the Geminiviridae family. The ribozyme showed approximately 33% cleavage activity on synthetic rep transcript within 1h under in vitro conditions, whereas the mutant ribozyme, designed to lack the catalytic activity but target the same site, showed no cleavage. The in vivo efficiency of ribozyme was evaluated in Saccharomyces cerevisiae as it can act as a surrogate host for replication of the MYMIV-DNA and lacks RNAi machinery. In the presence of the ribozyme, growth of the yeast cells that are dependent on geminiviral replication was inhibited by 30% and cellular generation time was increased by 2h. The RT-PCR analysis showed a maximum of about 50% reduction in the rep mRNA level in presence of the ribozyme compared to its noncatalytic mutant control. About 65% decrease in geminiviral DNA replication was observed due to the downregulation of replication initiator protein by the ribozyme. These results raise the possibility of engineering resistance to geminiviruses employing the ribozyme approach.
Collapse
Affiliation(s)
- Ushasri Chilakamarthi
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, India
| | | | | |
Collapse
|
45
|
Vadivukarasi T, Girish KR, Usha R. Sequence and recombination analyses of the geminivirus replication initiator protein. J Biosci 2007; 32:17-29. [PMID: 17426377 DOI: 10.1007/s12038-007-0003-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The sequence motifs present in the replication initiator protein (Rep) of geminiviruses have been compared with those present in all known rolling circle replication initiators. The predicted secondary structures of Rep representing each group of organisms have been compared and found to be conserved. Regions of recombination in the Rep gene and the adjoining 5' intergenic region (IR)of representative species of Geminiviridae have been identified using Recombination Detection Programs. The possible implications of such recombinations on the increasing host range of geminivirus infections are discussed.
Collapse
Affiliation(s)
- T Vadivukarasi
- Center for Excellence in Bioinformatics, School of Biotechnology, Madurai Kamaraj University, Madurai 625 21, India
| | | | | |
Collapse
|
46
|
Lopez-Ochoa L, Ramirez-Prado J, Hanley-Bowdoin L. Peptide aptamers that bind to a geminivirus replication protein interfere with viral replication in plant cells. J Virol 2006; 80:5841-53. [PMID: 16731923 PMCID: PMC1472579 DOI: 10.1128/jvi.02698-05] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The AL1 protein of tomato golden mosaic virus (TGMV), a member of the geminivirus family, is essential for viral replication in plants. Its N terminus contains three conserved motifs that mediate origin recognition and DNA cleavage during the initiation of rolling-circle replication. We used the N-terminal domain of TGMV AL1 as bait in a yeast two-hybrid screen of a random peptide aptamer library constrained in the active site of the thioredoxin A (TrxA) gene. The screen selected 88 TrxA peptides that also bind to the full-length TGMV AL1 protein. Plant expression cassettes corresponding to the TrxA peptides and a TGMV A replicon encoding AL1 were cotransfected into tobacco protoplasts, and viral DNA replication was monitored by semiquantitative PCR. In these assays, 31 TrxA peptides negatively impacted TGMV DNA accumulation, reducing viral DNA levels to 13 to 64% of those of the wild type. All of the interfering aptamers also bound to the AL1 protein of cabbage leaf curl virus. A comparison of the 20-mer peptides revealed that their sequences are not random. The alignments detected seven potential binding motifs, five of which are more highly represented among the interfering peptides. One motif was present in 18 peptides, suggesting that these peptides interact with a hot spot in the AL1 N terminus. The peptide aptamers characterized in these studies represent new tools for studying AL1 function and can serve as the basis for the development of crops with broad-based resistance to single-stranded DNA viruses.
Collapse
Affiliation(s)
- Luisa Lopez-Ochoa
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA
| | | | | |
Collapse
|
47
|
Settlage SB, See RG, Hanley-Bowdoin L. Geminivirus C3 protein: replication enhancement and protein interactions. J Virol 2005; 79:9885-95. [PMID: 16014949 PMCID: PMC1181577 DOI: 10.1128/jvi.79.15.9885-9895.2005] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Accepted: 04/23/2005] [Indexed: 11/20/2022] Open
Abstract
Most dicot-infecting geminiviruses encode a replication enhancer protein (C3, AL3, or REn) that is required for optimal replication of their small, single-stranded DNA genomes. C3 interacts with C1, the essential viral replication protein that initiates rolling circle replication. C3 also homo-oligomerizes and interacts with at least two host-encoded proteins, proliferating cell nuclear antigen (PCNA) and the retinoblastoma-related protein (pRBR). It has been proposed that protein interactions contribute to C3 function. Using the C3 protein of Tomato yellow leaf curl virus, we examined the impact of mutations to amino acids that are conserved across the C3 protein family on replication enhancement and protein interactions. Surprisingly, many of the mutations did not affect replication enhancement activity of C3 in tobacco protoplasts. Other mutations either enhanced or were detrimental to C3 replication activity. Analysis of mutated proteins in yeast two-hybrid assays indicated that mutations that inactivate C3 replication enhancement activity also reduce or inactivate C3 oligomerization and interaction with C1 and PCNA. In contrast, mutated C3 proteins impaired for pRBR binding are fully functional in replication assays. Hydrophobic residues in the middle of the C3 protein were implicated in C3 interaction with itself, C1, and PCNA, while polar resides at both the N and C termini of the protein are important for C3-pRBR interaction. These experiments established the importance of C3-C3, C3-C1, and C3-PCNA interactions in geminivirus replication. While C3-pRBR interaction is not required for viral replication in cycling cells, it may play a role during infection of differentiated cells in intact plants.
Collapse
Affiliation(s)
- Sharon B Settlage
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, 27695-7622, USA.
| | | | | |
Collapse
|
48
|
Zhang J, Hogenhout SA, Nault LR, Hoy CW, Miller SA. Molecular and symptom analyses of phytoplasma strains from lettuce reveal a diverse population. PHYTOPATHOLOGY 2004; 94:842-849. [PMID: 18943104 DOI: 10.1094/phyto.2004.94.8.842] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT Epidemics of aster yellows in lettuce in Ohio are caused by at least seven distinct phytoplasma strains in the aster yellows (AY) group. Five of the strains are newly reported: AY-BW, AY-WB, AY-BD3, AY-SS, and AY-SG. All seven strains were characterized based on symptoms in aster and lettuce, and by polymerase chain reaction (PCR). Strain AY-BD2 (formerly 'Bolt') causes yellowing and leaf distortion in lettuce and bolting in aster, whereas strain AY-S (formerly 'Severe') causes stunting, leaf clustering, and phyllody. Strain AY-WB causes yellowing and wilting in lettuce and witches'-broom in aster. Strain AY-SG induces horizontal growth in lettuce and aster plants. Strain AY-BW causes chlorosis of emerging leaves and abnormally upright growth of leaf petioles. AY-SS causes symptoms similar to those caused by AY-S but has a different PCR-restriction fragment length polymorphism (RFLP) banding pattern. Strains AY-BD2 and AY-BD-3 cause mild leaf and stem distortion in lettuce but are differentiated by PCR-RFLP. All phytoplasma strains collected from lettuce in Ohio belong to the 16SrI group. AY-WB belongs to the 16SrI-A subgroup and the other six belong to the 16SrI-B subgroup. Five of the seven strains were distinguished from each other by primer typing. The results of phylogenetic analyses of sequences of the 16S rRNA genes were basically consistent with the classification based on PCR-RFLP, in which AY-WB clustered with phytoplasmas of the 16rIA subgroup and the other Ohio lettuce strains clustered with phytoplasmas in the 16SrI-B subgroup.
Collapse
|
49
|
Arguello-Astorga G, Lopez-Ochoa L, Kong LJ, Orozco BM, Settlage SB, Hanley-Bowdoin L. A novel motif in geminivirus replication proteins interacts with the plant retinoblastoma-related protein. J Virol 2004; 78:4817-26. [PMID: 15078963 PMCID: PMC387707 DOI: 10.1128/jvi.78.9.4817-4826.2004] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Accepted: 12/09/2003] [Indexed: 11/20/2022] Open
Abstract
The geminivirus replication factor AL1 interacts with the plant retinoblastoma-related protein (pRBR) to modulate host gene expression. The AL1 protein of tomato golden mosaic virus (TGMV) binds to pRBR through an 80-amino-acid region that contains two highly predicted alpha-helices designated 3 and 4. Earlier studies suggested that the helix 4 motif, whose amino acid sequence is strongly conserved across geminivirus replication proteins, plays a role in pRBR binding. We generated a series of alanine substitutions across helix 4 of TGMV AL1 and examined their impact on pRBR binding using yeast two-hybrid assays. These experiments showed that several helix 4 residues are essential for efficient pRBR binding, with a critical residue being a leucine at position 148 in the middle of the motif. Various amino acid substitutions at leucine-148 indicated that both structural and side chain components contribute to pRBR binding. The replication proteins of the geminiviruses tomato yellow leaf curl virus and cabbage leaf curl virus (CaLCuV) also bound to pRBR in yeast dihybrid assays. Mutation of the leucine residue in helix 4 of CaLCuV AL1 reduced binding. Together, these results suggest that helix 4 and the conserved leucine residue are part of a pRBR-binding interface in begomovirus replication proteins.
Collapse
Affiliation(s)
- Gerardo Arguello-Astorga
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, USA
| | | | | | | | | | | |
Collapse
|
50
|
Castillo AG, Kong LJ, Hanley-Bowdoin L, Bejarano ER. Interaction between a geminivirus replication protein and the plant sumoylation system. J Virol 2004; 78:2758-69. [PMID: 14990696 PMCID: PMC353736 DOI: 10.1128/jvi.78.6.2758-2769.2004] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2003] [Accepted: 11/14/2003] [Indexed: 02/07/2023] Open
Abstract
Geminiviruses are small DNA viruses that replicate in nuclei of infected plant cells after accumulation of host replication machinery. Tomato golden mosaic virus (TGMV) and Tomato yellow leaf curl Sardinia virus (TYLCSV) encode a protein, RepAC1 (or Rep), that is essential for viral replication. Rep/RepAC1 is an oligomeric protein that binds to double-stranded DNA, catalyzes cleavage and ligation of single-stranded DNA, and is sufficient for host induction. It also interacts with several host proteins, including the cell cycle regulator, retinoblastoma, and essential components of the cell DNA replication machinery, like proliferating nuclear cell antigen (PCNA) and RFC-1. To identify other cellular proteins that interact with Rep/RepAC1 protein, a Nicotiana benthamiana cDNA library was screened with a yeast two-hybrid assay. The host cell sumoylation enzyme, NbSCE1 (N. benthamiana SUMO-conjugating enzyme, homolog to Saccharomyces cerevisiae UBC9), was found to interact specifically with RepAC1. Mapping studies localized the interaction to the N-terminal half of RepAC1. Effects on geminivirus replication were observed in transgenic plants with altered levels of SUMO, the substrate for UBC9.
Collapse
Affiliation(s)
- A G Castillo
- Department of Cellular Biology, Genetics and Animal Physiology, Málaga University, Málaga 29071, Spain
| | | | | | | |
Collapse
|