A member of a new genus in the Potyviridae infects Rubus

Susaimuthu, James; Tzanetakis, Ioannis E.; Gergerich, R. C.; Martín, Robert R.

doi:10.1016/j.virusres.2007.09.001

Cited by 54 publications

(32 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, from the results presented here, one possibility is that CTV progressively acquired genes for interacting with multiple hosts. Although viruses are known to have acquired nonconserved genes/domains (25,(34)(35)(36), the involvement of these genes to extend the virus host range had not been demonstrated. CTV has multiple genes required for systemic infection of different citrus hosts including three that are only needed for a subset of its hosts.…”

Section: Discussionmentioning

confidence: 99%

A plant virus evolved by acquiring multiple nonconserved genes to extend its host range

Satyanarayana

Robertson

Garnsey

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Viruses have evolved as combinations of genes whose products interact with cellular components to produce progeny virus throughout the plants. Some viral genes, particularly those that are involved in replication and assembly, tend to be relatively conserved, whereas other genes that have evolved for interactions with the specific host for movement and to counter host-defense systems tend to be less conserved. Closteroviridae encode 1-5 nonconserved ORFs. Citrus tristeza virus (CTV), a Closterovirus, possesses nonconserved p33, p18, and p13 genes that are expendable for systemic infection of the two laboratory hosts, Citrus macrophylla and Mexican lime. In this study, we show that the extended host range of CTV requires these nonconserved genes. The p33 gene was required to systemically infect sour orange and lemon trees, whereas either the p33 or the p18 gene was sufficient for systemic infection of grapefruit trees and the p33 or the p13 gene was sufficient for systemic infection of calamondin plants. Thus, these three genes are required for systemic infection of the full host range of CTV, but different genes were specific for different hosts. Remarkably, either of two genes was sufficient for infection of some citrus hybrids. These findings suggest that CTV acquired multiple nonconserved genes (p33, p18, and p13) and, as a result, gained the ability to interact with multiple hosts, thus extending its host range during the course of evolution. These results greatly extend the complexity of known virus-plant interactions.gene addition | host-specific activity | long-distance transport

show abstract

Section: Discussionmentioning

confidence: 99%

A plant virus evolved by acquiring multiple nonconserved genes to extend its host range

Satyanarayana

Robertson

Garnsey

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Whereas in typical potyviruses the 59 terminal region of the genome codes for a single serine proteinase (P1), the 59 terminal region of the genome of CVYV and SqVYV codes for two similar serine proteinases arranged in tandem (P1a and P1b), and the P1b has been shown to have RNA silencing suppression activity (Valli et al 2006;Li et al 2008). These P1b proteins, together with homologs in the Ipomovirus, Brambyvirus, and Poacevirus (or Susmovirus) genera form a group of P1 proteins that is phylogenetically and functionally distinct from the potyviral P1s, and the P1a proteins of CVYV and SqVYV (Valli et al 2007;Susaimuthu et al 2008;Fellers et al 2009;Tatineni et al 2009). …”

Section: Introductionmentioning

confidence: 99%

The specific binding to 21-nt double-stranded RNAs is crucial for the anti-silencing activity of Cucumber vein yellowing virus P1b and perturbs endogenous small RNA populations

Vallí¹,

Oliveros²,

Molnár³

et al. 2011

RNA

View full text Add to dashboard Cite

RNA silencing mediated by siRNAs plays an important role as an anti-viral defense mechanism in plants and other eukaryotic organisms, which is usually counteracted by viral RNA silencing suppressors (RSSs). The ipomovirus Cucumber vein yellowing virus (CVYV) lacks the typical RSS of members of the family Potyviridae, HCPro, which is replaced by an unrelated RSS, P1b. CVYV P1b resembles potyviral HCPro in forming complexes with synthetic siRNAs in vitro. Electrophoretic mobility shift assays showed that P1b, like potyviral HCPro, interacts with double-stranded siRNAs, but is not able to bind single-stranded small RNAs or small DNAs. These assays also showed a preference of CVYV P1b for binding to 21-nt siRNAs, a feature also reported for HCPro. However, these two potyvirid RSSs differ in their requirements of 2-nucleotide (nt) 39 overhangs and 59 terminal phosphoryl groups for siRNA binding. Copurification assays confirmed in vivo P1b-siRNA interactions. We have demonstrated by deep sequencing of small RNA populations interacting in vivo with CVYV P1b that the size preference of P1b for small RNAs of 21 nt also takes place in the plant, and that expression of this RSS causes drastic changes in the endogenous small RNA populations. In addition, a site-directed mutagenesis analysis strongly supported the assumption that P1b-siRNA binding is decisive for the anti-silencing activity of P1b and localized a basic domain involved in the siRNA-binding activity of this protein.

show abstract

“…Another strategy to counteract deleterious mutations is exhibited by replicases of many viruses of the Flexiviridae and some viruses of the Closteroviridae that contain an AlkB domain similar to the AlkB proteins in plant-infecting bacteria (6). However, Blackberry virus Y which represents a putative new genus of Potyviridae contains the AlkB domain inside the P1 proteinase (36). This virus is the only Potyviridae member besides CBSV and EuRSV that is known to carry an insertion of cellular origin.…”

mentioning

confidence: 99%

Cassava Brown Streak Virus ( Potyviridae ) Encodes a Putative Maf/HAM1 Pyrophosphatase Implicated in Reduction of Mutations and a P1 Proteinase That Suppresses RNA Silencing but Contains No HC-Pro

Mbanzibwa

Tian

Mukasa

et al. 2009

J Virol

109

115

View full text Add to dashboard Cite

The complete positive-sense single-stranded RNA genome of Cassava brown streak virus (CBSV; genus Ipomovirus; Potyviridae) was found to consist of 9,069 nucleotides and predicted to produce a polyprotein of 2,902 amino acids. It was lacking helper-component proteinase but contained a single P1 serine proteinase that strongly suppressed RNA silencing. Besides the exceptional structure of the 5-proximal part of the genome, CBSV also contained a Maf/HAM1-like sequence (678 nucleotides, 226 amino acids) recombined between the replicase and coat protein domains in the 3-proximal part of the genome, which is highly conserved in Potyviridae. HAM1 was flanked by consensus proteolytic cleavage sites for ipomovirus NIaPro cysteine proteinase. Homology of CBSV HAM1 with cellular Maf/HAM1 pyrophosphatases suggests that it may intercept noncanonical nucleoside triphosphates to reduce mutagenesis of viral RNA.

show abstract

A member of a new genus in the Potyviridae infects Rubus

Cited by 54 publications

References 38 publications

A plant virus evolved by acquiring multiple nonconserved genes to extend its host range

A plant virus evolved by acquiring multiple nonconserved genes to extend its host range

The specific binding to 21-nt double-stranded RNAs is crucial for the anti-silencing activity of Cucumber vein yellowing virus P1b and perturbs endogenous small RNA populations

Cassava Brown Streak Virus ( Potyviridae ) Encodes a Putative Maf/HAM1 Pyrophosphatase Implicated in Reduction of Mutations and a P1 Proteinase That Suppresses RNA Silencing but Contains No HC-Pro

Contact Info

Product

Resources

About