3-coterminal subgenomic RNAs and putative cis-acting elements of Grapevine leafroll-associated virus 3 reveals unique features of gene expression strategy in the genus AmpelovirusReportar como inadecuado




3-coterminal subgenomic RNAs and putative cis-acting elements of Grapevine leafroll-associated virus 3 reveals unique features of gene expression strategy in the genus Ampelovirus - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Virology Journal

, 7:180

First Online: 03 August 2010Received: 14 June 2010Accepted: 03 August 2010

Abstract

BackgroundThe family Closteroviridae comprises genera with monopartite genomes, Closterovirus and Ampelovirus, and with bipartite and tripartite genomes, Crinivirus. By contrast to closteroviruses in the genera Closterovirus and Crinivirus, much less is known about the molecular biology of viruses in the genus Ampelovirus, although they cause serious diseases in agriculturally important perennial crops like grapevines, pineapple, cherries and plums.

ResultsThe gene expression and cis-acting elements of Grapevine leafroll-associated virus 3 GLRaV-3; genus Ampelovirus was examined and compared to that of other members of the family Closteroviridae. Six putative 3-coterminal subgenomic sg RNAs were abundantly present in grapevine Vitis vinifera infected with GLRaV-3. The sgRNAs for coat protein CP, p21, p20A and p20B were confirmed using gene-specific riboprobes in Northern blot analysis. The 5-termini of sgRNAs specific to CP, p21, p20A and p20B were mapped in the 18,498 nucleotide nt virus genome and their leader sequences determined to be 48, 23, 95 and 125 nt, respectively. No conserved motifs were found around the transcription start site or in the leader sequence of these sgRNAs. The predicted secondary structure analysis of sequences around the start site failed to reveal any conserved motifs among the four sgRNAs. The GLRaV-3 isolate from Washington had a 737 nt long 5- nontranslated region NTR with a tandem repeat of 65 nt sequence and differed in sequence and predicted secondary structure with a South Africa isolate. Comparison of the dissimilar sequences of the 5-NTRs did not reveal any common predicted structures. The 3-NTR was shorter and more conserved. The lack of similarity among the cis-acting elements of the diverse viruses in the family Closteroviridae is another measure of the complexity of their evolution.

ConclusionsThe results indicate that transcription regulation of GLRaV-3 sgRNAs appears to be different from members of the genus Closterovirus. An analysis of the genome sequence confirmed that GLRaV-3 has an unusually long 5-NTR of 737 nt compared to other monopartite members of the family Closteroviridae, with distinct differences in the sequence and predicted secondary structure when compared to the corresponding region of the GLRaV-3 isolate from South Africa.

Electronic supplementary materialThe online version of this article doi:10.1186-1743-422X-7-180 contains supplementary material, which is available to authorized users.

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Autor: Sridhar Jarugula - Siddarame Gowda - William O Dawson - Rayapati A Naidu

Fuente: https://link.springer.com/







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