ABSTRACT
This chapter addresses the effects of dietary zinc on gene expression. There is substantial data on the regulation of metallothionein (MT) by dietary zinc under practical conditions to suggest zinc has regulatory control over some genes at the transcriptional level. The mechanism of transcriptional regulation of MT expression by the micronutrient may parallel that for other zinc-responsive genes. The turnover of MT has not been studied as well as the induction process. However, evidence has shown that the type of metal ions bound to MT has a direct influence on the stability of the protein to proteolytic activity. It was found that the kidney, liver, and intestine all demonstrated increases in MT mRNA abundance due to increased zinc in the diet, with no effect seen in brain MT levels. There is convincing evidence that resistance to many alkylating agents used in chemotherapy is directly related to MT expression.
