Metal elements and gene expression.

The transcriptional regulation of genes by metals is a biological function separate from structural and catalytic roles for metals in gene expression. Each of these functions relies on metals that enter cells from metabolic compartments derived from and influenced by the dietary metal supply. The intracellular metal pools provide an available source for binding to metalloregulatory proteins for transcriptional regulation. These proteins bind MRE sequences found in the promoters of some genes. The distribution of MRE sequences and of metalloregulatory proteins extends from microbial to mammalian systems. The bulk of the data on metal regulation of mammalian gene expression is from the perspective of positive transcriptional regulation. Nevertheless, negative regulation by metals could potentially occur. Transcriptional regulation of genes by nutritionally important metals must be viewed in the context of the other roles of metals in cellular structure and function. Investigators are rapidly delineating the involvement of metals in molecular biology in general and in gene expression in particular.