Fig. 3.

The acidic region harboring the nuclear export signal (NES) is critical for metal response in bat MTF-1. The subsegment encoding the acidic activation/NES region from human, bat and shrew MTF-1s was fused to the DNA binding domain of Gal4 transcription factor. As controls, the human domain was also provided in two mutant forms, one with a deletion of the NES motif and the other with a substitution of its own NES by the one of the mouse, as described in (Lindert et al. 2009). Dko7 cells were transfected with the indicated effector constructs, a reporter containing Gal4 binding sites and a reference gene. Two days later, cells were either kept untreated or treated for 4 h with zinc, and transcript levels were determined by the S1-assay. The bars represent the average of two independent experiments; gel bands of one of these experiments are shown above. Transcript levels with the zinc-induced fusion construct Gal4-human acidic domain are set to 100. nt, no metal treatment