() RNA binding assay. GST–RRM and GST were expressed in bacteria and purified. An aliquot of 1 μg of the protein was cross linked for 10 min at 254 nm with [P]UTP adenovirus RNA, treated with RNase A and analysed by 12.5% SDS–PAGE followed by autoradiography. Unlabelled ES cell total RNA was used as a competitor. The positions of the GST–RRM and GST proteins are indicated. () Subcellular distribution of Psc1 protein in Psc1, GFP–Psc1ΔRRM and GFP–RRM transfected COS-1 cells. Error bars indicate standard deviation. () COS-1 cell transfected with GFP–Psc1ΔRRM visualized by direct fluorescence (lower right) or anti-SC35 antibody (top right). Left panel shows merged images. () COS-1 cell transfected with GFP–RRM visualized by direct fluorescence (lower right) or anti-SC35 antibody (top right). Left panel shows merged images () COS-1 cell cotransfected with GFP–Psc1ΔRRM and Psc1–HA visualized by direct fluorescence (lower right) or anti-HA TRITC (top right). Left panels show merged images. () COS-1 cell cotransfected with GFP–RRM and Psc1–HA and visualized by direct fluorescence (lower right) or anti-HA TRITC (top right). Left panel shows merged images. Size bars represent 10 μm. Panel E is a confocal image, all other images were obtained by conventional microscopy.