Constitutive transcription of the gene for metallothionein in a cadmium-resistant yeast.
A cadmium-resistant strain of Saccharomyces cerevisiae produces a cadmium metallothionein encoded by the CUP1 gene as does a copper-resistant strain. The mechanism of expression of the gene is inducible by copper ions in the copper-resistant strain. However, assays of CUP1-specific mRNA revealed that the transcription of the CUP1 gene in the cadmium-resistant strain is constitutive and the rate of transcription is further increased by exposure to cadmium or copper ions. This result was confirmed by the appearance of constitutive-expression segregants from diploid crosses between the cadmium-resistant strain and a strain with a reporter gene having the promoter of CUP1.
Tohoyama
H
H
Department of Biology, Faculty of Science, Ehime University, Matsuyama, Japan.
Inagawa
A
A
Koike
H
H
Inouhe
M
M
Joho
M
M
Murayama
T
T
D002104:Cadmium / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008668:Metallothionein / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*; D014158:Transcription, Genetic
C004203:cadmium-binding protein; D002104:Cadmium; D003300:Copper; D008668:Metallothionein