ARGONAUTE10 promotes degradation of miR165/6 through SDN1 and SDN2 exonucleases

ARGONAUTE10 (AGO10) was first identified through genetic studies in the 90s; loss-of-function mutants (zwille, pinhead) show premature differentiation of the shoot apical meristem. Although the mechanism has remained uncertain, AGO10 has been shown to suppress accumulation of miR165/6, which are key regulators of a large number of developmentally important transcription factors. Yu, Ji, and Le et al. propose a model for miRNA degradation, and demonstrate the contributions of members of the family of SMALL RNA DEGRADING NUCLEASES (SDNs) in miRNA degradation. They also show that when bound by AGO10, miR165/6 degradation is enhanced, thus providing a molecular mechanism for AGO10 function. PLOS Biol. 10.1371/journal.pbio.2001272