Argonaute: a scaffold for the function of short regulatory RNAs

Argonaute is the central protein component of RNA-silencing mechanisms. It provides the platform for target-mRNA recognition by short regulatory guide RNA strands and the Slicer catalytic activity for mRNA cleavage in RNA interference. Multiple Argonaute subfamilies can be identified phylogenetically yet, despite this diversity, molecular and sequence analyses show that Argonaute proteins share common molecular properties and the capacity to function through a common mechanism. Recently, the members of the Piwi subfamily have been shown to interact with new classes of short regulatory RNAs, Piwi-interacting RNAs (piRNAs) and repeat-associated small interfering RNAs (rasiRNAs), which has implications for developmental processes and introduces a new dimension to the field of RNA silencing.