REGULATION OF HEAT-SHOCK GENES - A DNA-SEQUENCE UPSTREAM OF DROSOPHILA-HSP70 GENES IS ESSENTIAL FOR THEIR INDUCTION IN MONKEY CELLS

Heat-shock genes coding for heat-shock protein 70 (HSP70) in D. melanogaster were subcloned into an SV40/plasmid recombinant capable of replication in permissive monkey COS cells. Following transfection of COS cells, no significant amount of Drosophila hsp70 RNA was detected at 37.degree. C. A heat-shock at 43.degree. C or arsenite poisoning at 37.degree. C induced the massive production of Drosophila hsp70 RNA of correct size and faithful 5'' ends. After heat-shock, the efficiency of hsp70 transcription in COS cells containing 2-4 .times. 104 gene copies was found to be 15-30% of that measured in Drosophila on a per gene basis. By testing a series of 5'' deletion mutants in this inducible transcription assay, it was found that a sequence < 70 bp [base pair] long, directly upstream of the hsp70 gene, was essential for the heat or arsenite induction of transcription.