Cambronne, X.A. et al. Proc. Natl. Acad. Sci. USA published online (26 November 2012).

Individual microRNAs (miRNAs) can target up to hundreds of messenger RNAs (mRNAs) in the cell for silencing. To identify these targets, many methods capture miRNA as it interacts with mRNA by pulling down the gene-silencing machinery, such as by the immunoprecipitation of Argonaute proteins. But because targeted transcripts are subject to destabilization, isolation of these transient interactions can be problematic, especially for rarer transcripts. Cambronne et al. use a truncated and tagged version of the silencing protein GW182 that allows miRNA and transcripts to be recruited but prevents transcript destabilization. Using this 'RISCtrap' approach of pulling down the mutant GW182 and associated transcripts, they identify high-confidence neuronal target lists for three human miRNAs.