ISOLATION AND SEQUENCE OF HSP30, A YEAST HEAT-SHOCK GENE CODING FOR A HYDROPHOBIC MEMBRANE-PROTEIN

Using differential hybridization, a gene preferentially expressed during entry into stationary phase has been isolated. Subsequent analysis indicated that this gene corresponds to a heat-shock gene. The nucleotide sequence has been determined. It revealed a 332 aminoacid protein. No similarities to any previously known protein have been noted. The protein is very hydrophobic and is predicted to have a membraneous localisation. In agreement with this hypothesis, the analysis of membrane proteins from stationary-phase cells showed that a strain carrying this gene on a multicopy vector overproduces a protein of 30 kDa. This protein was recognized by antibodies directed against the N-terminal portion of the gene product. Considering its induction in response to heat shock and the apparent molecular weight of its product, this gene was designated HSP30.