Figure 4.

dFXR [the Drosophila homolog of the Fragile X Mental Retardation Protein (FMRP)] immunoprecipitates contain RISC activity. Drosophila S2 cells were transfected with expression vectors for the indicated T7-tagged cDNAs and double-stranded RNAs corresponding to luciferase. Protein was immunoprecipitated with anti-T7 tag affinity resin, and this resin was incubated for the indicated times with radiolabeled single-stranded RNA (ssRNA) for target (luciferase), or control (GFP). RISC activity was indicated by loss of targeted RNA.