Fig. 4. DYRK1A colocalizes with splicing factors in nuclear speckles. COS-7 cells were transfected with GFP-DYRK1A wildtype (A-C), GFP-DYRK1A 590-616 (D), and GFP-cyclin T1 433-533 and 503-533 (E) and immunostained with reported markers of different subnuclear compartments. In A, POD nuclear bodies were detected with an anti-PML antibody. In B, cells were cotransfected with HA-SUMO, and SUMO-conjugated dots were detected by using an anti-HA antibody. In C-E, SFCs were detected either with an antibody to the SR splicing factor SC35 (C, upper panel, D and E) or with an anti-Sm antibody (Y12) that recognizes sRNPs (C, lower panel). GFP fusion proteins were visualized directly by fluorescence microscopy (left column, green) and nuclear subcompartments by indirect immunofluorescence, using Cy3-conjugated goat anti-rabbit (A) and Texas Red-labeled sheep anti-mouse (B-E) as secondary antibodies (middle column, red). Merged images are also shown (right column). All the images in this figure, except in E, were taken by confocal microscopy for clearer confirmation of the colocalization results.