Molecular cloning of sequences encoding the human heat-shock proteins and their expression during hyperthermia

Abstract

Plasmids containing cDNA copies of mRNAs induced in HeLa cells by heat shock have been isolated and characterized. In vitro translation of RNAs selected by hybridization to plasmid DNAs identified sequences representing the three major classes ∗∗ ∗∗ The 89-kDa hsp referred to in this manuscript was described as 80 kDa in our previous publication (Hickey and Weber, 1982a). This protein is the same as the 90-kDa stress protein of HeLa cells (Welch and Feramisco, 1982; Welch et al., 1983). (89, 70 and 27-kDa) of heat-shock proteins (hsp) and a 60-kDa minor hsp. Plasmids with inserts specific for the 27, 60, and 70-kDa hsp each hybridize with a single discrete size class of heat-inducible mRNA. Plasmids specific for the 89-kDa protein, however, hybridize with either a 2.7-or 2.95-kb mRNA species. Both mRNAs are coordinately induced during heat shock. We show that the characteristic pattern of induction and repression of each class of hsp during sustained hyperthermia is the result of changes in the steady state level of each mRNA.