A role for HuR in regulation of Hmga2. (A) HuR binding sites correspond to up-regulating 50mers. Location of HuR binding sites (black boxes) according to available PAR-CLIP data (Kishore et al. 2011) displayed parallel to a heatmap representation of the Hmga2 3′-UTR 50mer reporter data. (B) Evaluation of HuR knockdown. A549 cells were infected with two different shRNA hairpins targeting the HuR mRNA, and the effect on HuR transcript levels determined with qRT-PCR; two different hairpins (targeting GFP and LacZ) were used as negative controls (n = 3). Error bars indicate one standard deviation. (C) Reporter assays of selected Hmga2 50mer reporters, and one random 50mer control reporter, in HuR knockdown cells. Reporter expression, normalized to a second inert random-sequence control (right-most data), was compared between HuR knockdown cells and cells infected with control shRNAs (targeting GFP). Significant changes in reporter expression were determined using Wilcoxon rank-sum tests (n = 12; P < 0.05 and 1 × 10−3 indicated by * and **, respectively).
