Fig. 8. hADAT1 is a nucleocytoplasmic shuttling protein that is excluded from the nucleolus. Schematic representation of the homology between hADAR1, hADAR2 and hADAT1. The three enzymes contain a deaminase domain and only hADAT1 does not contain dsRNA-binding domains. The most important domains of hADAR1 are indicated as follow: ZBDs, Z-DNA-binding domains (light gray); dsRBDs, double-stranded RNA binding domains (black boxes); deaminase domain (dark gray box). The size of the proteins are indicated at their C-termini as the number of amino acids. HeLa cells were transfected with GFP-ADAT1 and fused with murine NIH 3T3 cells. The heterokaryons were incubated in the presence of emetine. Immunostaining with anti-hnRNP C was used as control. In contrast to hnRNP C, which remains restricted to the transfected HeLa nucleus, GFP-ADAT1 migrates to the murine nuclei. The dashed lines indicate the contour of the murine nuclei in the heterokaryon. Incubation of HeLa cells expressing GFP-ADAT1 at 4°C in the presence of emetine shows that the protein does not leak to the cytoplasm. Bar, 10 µm.