Editors' ChoiceImmunology

Dicing with Viral Defense

Science's STKE  11 Jul 2006:
Vol. 2006, Issue 343, pp. tw226
DOI: 10.1126/stke.3432006tw226

In RNA silencing, Dicer endonuclease cleaves double-stranded RNAs to generate small interfering (si) RNAs that target complementary RNA sequences. The plant Arabidopsis has four Dicer-like (DCL) enzymes (DCL1 to DCL4) that are involved in the genesis of micro (mi) RNAs, natural antisense siRNAs, repeat-associated siRNAs, and trans-acting siRNAs, respectively. The role that the DCLs play in viral infection is less clearly understood. Deleris et al. show that the Arabidopsis dicers have equally distinct roles in defending the plants from infection, with DCL4 and DCL2 having major and partially redundant roles in incorporating viral siRNAs into antiviral effector RISCs. DCL4 also prevents viral movement outside the plant vasculature.

A. Deleris, J. Gallego-Bartolome, J. Bao, K. D. Kasschau, J. C. Carrington, O. Voinnet, Hierarchical action and inhibition of plant Dicer-like proteins in antiviral defense. Science 313, 68-71 (2006). [Abstract] [Full Text]

P. M. Waterhouse, A. F. Fusaro, Viruses face a double defense by plant small RNAs. Science 313, 54-55 (2006). [Summary] [Full Text]