Dataset Information

Suppression of methylation-mediated transcriptional gene silencing by ?C1-SAHH protein interaction during geminivirus-betasatellite infection.

ABSTRACT: DNA methylation is a fundamental epigenetic modification that regulates gene expression and represses endogenous transposons and invading DNA viruses. As a counter-defense, the geminiviruses encode proteins that inhibit methylation and transcriptional gene silencing (TGS). Some geminiviruses have acquired a betasatellite called DNA ?. This study presents evidence that suppression of methylation-mediated TGS by the sole betasatellite-encoded protein, ?C1, is crucial to the association of Tomato yellow leaf curl China virus (TYLCCNV) with its betasatellite (TYLCCNB). We show that TYLCCNB complements Beet curly top virus (BCTV) L2? mutants deficient for methylation inhibition and TGS suppression, and that cytosine methylation levels in BCTV and TYLCCNV genomes, as well as the host genome, are substantially reduced by TYLCCNB or ?C1 expression. We also demonstrate that while TYLCCNB or ?C1 expression can reverse TGS, TYLCCNV by itself is ineffective. Thus its AC2/AL2 protein, known to have suppression activity in other geminiviruses, is likely a natural mutant in this respect. A yeast two-hybrid screen of candidate proteins, followed by bimolecular fluorescence complementation analysis, revealed that ?C1 interacts with S-adenosyl homocysteine hydrolase (SAHH), a methyl cycle enzyme required for TGS. We further demonstrate that ?C1 protein inhibits SAHH activity in vitro. That ?C1 and other geminivirus proteins target the methyl cycle suggests that limiting its product, S-adenosyl methionine, may be a common viral strategy for methylation interference. We propose that inhibition of methylation and TGS by ?C1 stabilizes geminivirus/betasatellite complexes.

SUBMITTER: Yang X

PROVIDER: S-EPMC3197609 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Suppression of methylation-mediated transcriptional gene silencing by βC1-SAHH protein interaction during geminivirus-betasatellite infection.

Yang Xiuling X Xie Yan Y Raja Priya P Li Sizhun S Wolf Jamie N JN Shen Qingtang Q Bisaro David M DM Zhou Xueping X

PLoS pathogens 20111020 10

DNA methylation is a fundamental epigenetic modification that regulates gene expression and represses endogenous transposons and invading DNA viruses. As a counter-defense, the geminiviruses encode proteins that inhibit methylation and transcriptional gene silencing (TGS). Some geminiviruses have acquired a betasatellite called DNA β. This study presents evidence that suppression of methylation-mediated TGS by the sole betasatellite-encoded protein, βC1, is crucial to the association of Tomato y ...[more]

PMID: 22028660

Similar Datasets

Project description:BackgroundSmall RNA (sRNA)-guided RNA silencing is a critical antiviral defense mechanism employed by a variety of eukaryotic organisms. Although the induction of RNA silencing by bipartite and monopartite begomoviruses has been described in plants, the nature of begomovirus/betasatellite complexes remains undefined.Methodology/principal findingsSolanum lycopersicum plant leaves systemically infected with Tomato yellow leaf curl China virus (TYLCCNV) alone or together with its associated betasatellite (TYLCCNB), and Nicotiana benthamiana plant leaves systemically infected with TYLCCNV alone, or together with TYLCCNB or with mutant TYLCCNB were harvested for RNA extraction; sRNA cDNA libraries were then constructed and submitted to Solexa-based deep sequencing. Both sense and anti-sense TYLCCNV and TYLCCNB-derived sRNAs (V-sRNAs and S-sRNAs) accumulated preferentially as 22 nucleotide species in infected S. lycopersicum and N. benthamiana plants. High resolution mapping of V-sRNAs and S-sRNAs revealed heterogeneous distribution of V-sRNA and S-sRNA sequences across the TYLCCNV and TYLCCNB genomes. In TYLCCNV-infected S. lycopersicum or N. benthamiana and TYLCCNV and βC1-mutant TYLCCNB co-infected N. benthamiana plants, the primary TYLCCNV targets were AV2 and the 5' terminus of AV1. In TYLCCNV and betasatellite-infected plants, the number of V-sRNAs targeting this region decreased and the production of V-sRNAs increased corresponding to the overlapping regions of AC2 and AC3, as well as the 3' terminal of AC1. βC1 is the primary determinant mediating symptom induction and also the primary silencing target of the TYLCCNB genome even in its mutated form.Conclusions/significanceWe report the first high-resolution sRNA map for a monopartite begomovirus and its associated betasatellite using Solexa-based deep sequencing. Our results suggest that viral transcript might act as RDR substrates resulting in dsRNA and secondary siRNA production. In addition, the betasatellite affected the amount of V-sRNAs detected in S. lycopersicum and N. benthamiana plants.

Dataset Information

Suppression of methylation-mediated transcriptional gene silencing by ?C1-SAHH protein interaction during geminivirus-betasatellite infection.

Publications

Suppression of methylation-mediated transcriptional gene silencing by βC1-SAHH protein interaction during geminivirus-betasatellite infection.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets