ISSN:
0749-503X
Keywords:
Metallothionein
;
resistance to metal ions
;
expression vectors
;
CUP1
;
β-galactosidase
;
upstream activation sequences
;
recombinant DNA
;
yeast
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Shuttle plasmids, pE1.CUP1B and pE1.CUP1E of 10·6 kb, have been constructed between the metallothioneinencoding CUP1 gene of Saccharomyces cerevisiae and a vector capable of replication in Kluyveromyces lactis. Introduction of these plasmids into K. lactis confers resistance to copper as well as to cadmium and silver. Resistance to these latter metal ions, in the absence of induction by copper, suggested that the CUP1 gene is constitutively expressed in the foreign background. Introduction of the lacZ reporter gene from Escherichia coli into a cloning site downstream from the CUP1 promoter showed that expression of this gene is constitutive in K. lactis but in S. cerevisiae induction by copper is necessary. Sequences upstream from the CUP1 promoter are involved in the constitutive expression since deletion of 91 nucleotides from this region abolishes metal resistance. It is suggested that a K. lactis protein, normally involved in activating transcription of the resident CUP1 gene in the presence of copper, can promote transcription in the absence of metal ion by binding to the upstream activation sequence of the introduced CUP1 gene.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/yea.320070206
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