Overexpression of DDX1 in HeLa cells restores Rev nucleolar localization disrupted by Nullbasic. HeLa cells were transfected with HA-DDX1 alone (row 1), MYC-Rev with HA-DDX1 (row 2). Nullbasic (NB)-mCherry with HA-DDX1 (row 3) or MYC-Rev with HA-DDX1 and NB-mCherry (row 4). Fixed cells were immunostained with anti-MYC (green) and anti-HA (magenta) antibodies and were visualized alone with NB-mCherry (red) by fluorescence microscopy. Nuclei were stained with DAPI. The overlay panels show the merge of the MYC-Rev panel with the HA-DDX1 panels (row 1, 2, and 4) and the NB-mCherry panel with HA-DDX1 panel (row 3). Images are representative of at least five fields selected randomly from three independent experiments.