Figure 4.

The HuR NLS confers shuttling activity. (A). Schematic representation of the NPc fusion proteins assayed in Fig. 4B. (B) Heterokaryon fusion assays of NPc-M1, -M7, and -M10. HeLa cells were transiently transfected with NPc fusion proteins containing HuR sequences M1, M7, or M10. Heterokaryon fusion and staining assays were performed as described in Fig. 2, except for use of anti-myc mAb 9E10. Mouse nuclei in the heterokaryons are indicated with arrows. The NPc-NLS was analyzed as a negative control.