Fig. 3. Activation of cellular kinases by ZIP7 overexpression or zinc treatment. MCF-7 cells were transfected with or without wild-type ZIP7 and treated with or without zinc for 10 minutes. Tyrosine phosphorylation of selected RTKs and site-specific phosphorylation of selected kinases were determined using the phospho-RTK (A), phospho-kinase (B), and phospho-MAPK (C) antibody arrays (R&D systems). Signals for each kinase are presented as a pair of duplicate spots, with three pairs of dark reference spots on the upper left, upper right, and lower left corners for alignment. The kinases that show any conspicuous changes in phosphorylation (>10 000 density units) in the non-transfected zinc-treated cells (MCF-7 + Zn) or the transfected non-treated cells (wt-ZIP7) when compared to the non-transfected and non-treated cells (MCF-7) are indicated. In addition, the kinases that show any conspicuous changes in phosphorylation in the transfected zinc-treated cells (wt-ZIP7 + Zn) when compared to the non-transfected zinc-treated cells (MCF-7 + Zn) are also indicated. Average densitometric values for these kinases are shown in bar graphs. The experiments were performed once for the phospho-RTK and phospho-MAPK arrays and twice for the phospho-kinase arrays. Statistical significance compares wt-ZIP7 or MCF-7 + Zn to MCF-7 and wt-ZIP7 + Zn to MCF-7 + Zn. * = p < 0.05, ** = p < 0.01.