Isolation and functional analysis of chicken 90-kDa heat shock protein gene promoter.

We report the nucleotide sequence of a 2652 bp derived from a chicken 90-kDa heat shock protein (hsp 90) genomic clone. This fragment contains 890 bp of the 5' flanking region and 1762 bp of structural gene sequence encoding the first 85 amino acids of the protein. The start site of transcription was determined by primer extension and RNase mapping. Two introns have been identified. The first intron presents two features in common with the unique intron of the hsp 83 of drosophila: its location just before the ATG initiation codon and its length of approximately 1.3 Kb. The 5' flanking region contains a TATAA element, a CCAAT box and several putative cis-regulatory elements that might account for the basal level of expression and developmental regulation of the gene. Functional analyses show that hsp 90 gene expression is constitutive and heat inducible and that a full heat shock response requires the cooperativity of two distinct blocks of overlapping heat shock response elements.