FIG. 2.

Amino acids 133 to 226 are essential for nuclear localization of hMTF-1. (A and B) MTF-1 fused to GFP, with or without deletions in the zinc finger region, was transfected into U2OS (human osteosarcoma) cells. Thirty-six hours after transfection cells were treated with 100 μM zinc sulfate or 10 ng/ml LMB for 2 h or left untreated. Cells were fixed, and subcellular localization was monitored by GFP fluorescence. For quantification, 200 cells each were classified into the indicated categories (c, cytoplasm; n, nucleus). Nuclei were visualized by DAPI staining. nt, not treated; wt, wild type. (C) Sequence of the region necessary and sufficient for the nuclear localization of hMTF-1. Basic amino acids are highlighted in yellow. ZF1, zinc finger 1.