FIGURE 6.

HuR is required for RA-induced nuclear translocation of CRABP2. A, M-2^−/− cells were transduced with lentiviral particles encoding shRNAs targeting luciferase (shCtrl) or HuR (shHuR) and selected with puromycin to generate cell lines stably expressing the shRNAs. Immunoblotting demonstrates down-regulation of HuR in the cell line stably expressing shRNA targeting HuR. B, cells were cultured in delipidated medium and transfected with vector encoding FLAG-CRABP2. FLAG-CRABP2 was immunostained in untreated cells and in cells treated with RA for 30 min and visualized using confocal microscopy. DAPI was used to visualize nuclei. Scale bars, 20 μm. C, genes involved in nuclear import/export that were found by transcriptome analysis (Fig. 1) to be down-regulated upon decreasing the expression of HuR.