8z4a

Structural highlights

Function

DRB4_ARATH Double-stranded RNA-binding protein involved in RNA-mediated post-transcriptional gene silencing (PTGS). Functions in the trans-acting small interfering RNAs (ta-siRNAs) biogenesis by binding and assisting DICER-LIKE 4 (DCL4). Required for DCL4 activity. Required for the 21 nucleotide ta-siRNAs production of the TAS3 transcript in leaves but not in flowers. Plays an important role in silencing RNA of both DNA and RNA viruses. Involved with argonaute 7 (AGO7) and RDR6 in turnip crinkle virus (TCV) silencing. May not be directly involved in viral siRNA production. May stabilize the 21 nucleotide viral siRNAs and deliver them to the RISC complex. Targeted by the viral silencing suppressor (VSR) transactivator/viroplasmin (TAV) protein of the cauliflower mosaic virus (CaMV) that inactivates DRB4 function in RNA silencing. Probably not involved in the guide strand selection from RNA duplexes. Involved in leaf morphology through its function in ta-siRNA-mediated silencing.^{[1] [2] [3] [4]}

References

1. ↑ Adenot X, Elmayan T, Lauressergues D, Boutet S, Bouche N, Gasciolli V, Vaucheret H. DRB4-dependent TAS3 trans-acting siRNAs control leaf morphology through AGO7. Curr Biol. 2006 May 9;16(9):927-32. PMID:16682354 doi:http://dx.doi.org/10.1016/j.cub.2006.03.035
2. ↑ Nakazawa Y, Hiraguri A, Moriyama H, Fukuhara T. The dsRNA-binding protein DRB4 interacts with the Dicer-like protein DCL4 in vivo and functions in the trans-acting siRNA pathway. Plant Mol Biol. 2007 Apr;63(6):777-85. Epub 2007 Jan 14. PMID:17221360 doi:http://dx.doi.org/10.1007/s11103-006-9125-8
3. ↑ Curtin SJ, Watson JM, Smith NA, Eamens AL, Blanchard CL, Waterhouse PM. The roles of plant dsRNA-binding proteins in RNAi-like pathways. FEBS Lett. 2008 Aug 6;582(18):2753-60. doi: 10.1016/j.febslet.2008.07.004. Epub, 2008 Jul 14. PMID:18625233 doi:http://dx.doi.org/10.1016/j.febslet.2008.07.004
4. ↑ Qu F, Ye X, Morris TJ. Arabidopsis DRB4, AGO1, AGO7, and RDR6 participate in a DCL4-initiated antiviral RNA silencing pathway negatively regulated by DCL1. Proc Natl Acad Sci U S A. 2008 Sep 23;105(38):14732-7. doi:, 10.1073/pnas.0805760105. Epub 2008 Sep 17. PMID:18799732 doi:http://dx.doi.org/10.1073/pnas.0805760105