The CUP2 gene product regulates the expression of the CUP1 gene, coding for yeast metallothionein.

Dynamic Regulation of Copper Uptake and Detoxification Genes in Saccharomyces cerevisiae

“…Elegant genetic screens have identified genes that are responsible for Cu uptake under nutritional conditions when essential levels of Cu ions are present in the cell (10,25), distribution to appropriate subcellular compartments (8,15,31,49), and detoxification under toxic conditions when Cu ions are present in excess (7,40,41,45). At the nutritional level, Cu uptake into yeast cells is mediated by two membrane-associated high-affinity Cu(I) transporters, encoded by CTR1 and CTR3 (10,25), and a cell surface Cu(II)/Fe(III) reductase, encoded by the FRE1 gene, which reduces Cu(II) to Cu(I) prior to uptake (14,21).…”

Phosphorylation and Cu+Coordination-dependent DNA Binding of the Transcription Factor Mac1p in the Regulation of Copper Transport

“…The primary sequence indicates that the Mac1p may sense copper ions through direct copper ion coordination (7), similar to the two other known copper-sensing factors Ace1p and Amt1p (11)(12)(13)(14). Biochemical studies show that the separated DNA-binding domain and the activation domain of Mac1p expressed in the Escherichia coli both bind Cu ϩ ions (15).…”

In Vivo Competition between Plastocyanin and a Copper-Dependent Regulator of the Chlamydomonas reinhardtii Cytochrome c6 Gene

“…It is unlikely that the copper-binding regulator in C. reinhardtii is related to the yeast copper-dependent activators of transcription (2,5,27,32,35). First, the regulatory circuits display distinctly different metal specificities (10).…”

“…Thiele, personal communication). Finally, the C reinhardtii regulator prevents transcription in the metalated form, whereas the Saccharomyces cerevisiae regulator activates transcription in the metalated form (5,29,32). It is more likely that the copper-binding regulator in C. reinhardtii evolved independently with a different function-i.e.…”