METAL-ION REGULATION OF GENE-EXPRESSION IN YEAST

Metal-responsive transcription factors exist in yeast to modulate expr ession of genes that encode proteins involved in cellular uptake of co pper, iron and zinc ions. These signal transduction pathways function in the cellular regulation of the intracellular concentration of free metal ions. A second component of metal homeostasis is the regulation of metal-ion binding through protein-mediated metallation. Copper-spec ific chaperones exist in yeast that route copper ions to the site of b iosynthesis of copper-metalloenzymes.