PMID:21883552

Citation	Jakubiec, A, Yang, SW and Chua, NH (2012) Arabidopsis DRB4 protein in antiviral defense against Turnip yellow mosaic virus infection. Plant J. 69:14-25
Abstract	RNA silencing is an important antiviral mechanism in diverse eukaryotic organisms. In Arabidopsis DICER-LIKE 4 (DCL4) is the primary antiviral Dicer, required for the production of viral small RNAs from positive-strand RNA viruses. Here, we showed that DCL4 and its interacting partner dsRNA-binding protein 4 (DRB4) participate in the antiviral response to Turnip yellow mosaic virus (TYMV), and that both proteins are required for TYMV-derived small RNA production. In addition, our results indicate that DRB4 has a negative effect on viral coat protein accumulation. Upon infection DRB4 expression was induced and DRB4 protein was recruited from the nucleus to the cytoplasm, where replication and translation of viral RNA occur. DRB4 was associated with viral RNA in vivo and directly interacted in vitro with a TYMV RNA translational enhancer, raising the possibility that DRB4 might repress viral RNA translation. In plants the role of RNA silencing in viral RNA degradation is well established, but its potential function in the regulation of viral protein levels has not yet been explored. We observed that severe infection symptoms are not necessarily correlated with enhanced viral RNA levels, but might be caused by elevated accumulation of viral proteins. Our findings suggest that the control of viral protein as well as RNA levels might be important for mounting an efficient antiviral response.
Links	PubMed PMC3240694 Online version:10.1111/j.1365-313X.2011.04765.x
Keywords	Arabidopsis/genetics; Arabidopsis/metabolism; Arabidopsis/virology; Capsid Proteins/metabolism; Cell Nucleus/metabolism; Host-Pathogen Interactions; Plant Diseases/virology; Protein Biosynthesis; RNA, Transfer/chemistry; RNA, Transfer/metabolism; RNA, Viral/metabolism; RNA-Binding Proteins/genetics; RNA-Binding Proteins/metabolism; Ribonuclease III/genetics; Ribonuclease III/metabolism; Tymovirus/pathogenicity
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
ARATH:DRB4		GO:0051607: defense response to virus	ECO:0000315:		P		Fig. 1.B. and 1.C. show that drb4 mutants lacking DRB4 have enhanced severity of virus infection symptoms. Viral coat protein levels are higher in drb4 mutants and dcl4 mutants compared to wildtype. However, Fig. 3. shows that viral RNA levels are not elevated (unlike in dcl4 mutants), suggesting that DRB4 does not act in viral gene silencing.	complete CACAO 8230
ARATH:DRB4	involved_in	GO:0051607: defense response to virus	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete

References

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