Description
To obtain evidence that Argonaute (AGO) crosslink-centered regions (CCRs) indeed contain functional miRNA-binding sites, we blocked 25 of the most abundant miRNAs in HEK 293 cells (Figure 5C of PMID 20371350) by transfection of a cocktail of 2'-O-methyl-modified antisense oligoribonucleotides and monitored the changes in mRNA stability by microarrays (Figure 7A of PMID 20371350). Consistent with previous studies of individual miRNAs (Grimson et al., 2007), the magnitude of the destabilization effects of transcripts containing at least one CCR depended on the length of the seed-complementary region and dropped from 9-mer to 8-mer to 7-mer to 6-mer matches (Figure 7B of PMID 20371350). We did not find evidence for significant destabilization of transcripts that only contained imperfectly paired seed regions.