Review. Actions of plant Argonautes: Predictable or unpredictable? (COPB $)

The Arabidopsis genome encodes nine Argonaute proteins and an AGO pseudogene. The nine functional proteins fall into three clades based on sequence. Ma and Zhang update what we know about these proteins. It turns out, the simple assumptions made early on have not entirely been borne out. For example, AGO1 helps miRNAs carry out their functions (slicing and translational repression), but it also has roles in the nucleus, as a transcriptional repressor and transactivator. The finding that this and other AGO proteins can have multiple roles raises questions about how these functions are coordinated. Further, it indicates that the classification of AGO function based on phylogeny needs to be re-evaluated. (Summary by Mary Williams) Curr. Opin. Plant Biol. 10.1016/j.pbi.2018.05.007