FMRP binds specifically to RhoC RNA. RNA electrophoretic mobility shift assay was performed to verify direct interaction between RhoC RNA and recombinant FMRP as described in the Material and Methods. Lane 1, biotin labeled RhoC RNA alone. Lane 2, biotin labeled RhoC RNA plus FMRP. Lanes 3–6, biotin labeled RhoC RNA plus FMRP with increasing concentrations of unlabeled RhoC RNA. Lanes 7–10 biotin labeled RhoC RNA plus FMRP with increasing concentrations of non-specific competitor RNA. Both unlabeled RNA competitors are at 10X, 20X, 40X, 100X fold excess of the biotin labeled RhoC RNA.