Figure 7.

The hDrn1 protein shuttles between the nucleus and the cytoplasm as hDbr1. Expression vectors encoding hnRNP A1, C1, hDbr1 and hDrn1 with myc-tag were transfected into HeLa cells. After expression of the transfected cDNAs, the cells were fused using PEG with mouse NIH3T3 cells to form heterokaryons and incubated in culture medium containing 100 μg/mL cycloheximide for two hours. The heterokaryon cells were then fixed and stained for immunofluorescence microscopy with anti-myc tag antibody (panel FITC) to localize the proteins, and Hoechst 33342 (panel Hoechst), which distinguishes the human and mouse nuclei within the heterokaryon. The arrows indicate the mouse nuclei.