Duplicated heavy metal control sequences of the mouse metallothionein-I gene.

Abstract

Evidence is presented that 2 distinct regions of the DNA upstream from the mouse metallothionein-I gene contain metal-responsive regulatory sites. This result was obtained by analyzing a systematic series of deletion, insertion, duplication, and clustered point mutations introduced into cultured cells on an SV40 a plasmid vector. The 2 upstream regions contain a duplicated evolutionarily conserved DNA sequence. While either upstream region is sufficient to confer heavy metal reponsiveness, both are required to give maximal levels of induced transcription.