STRUCTURE AND ORGANIZATION OF A MURINE GENE ENCODING SMALL HEAT-SHOCK PROTEIN HSP25

The structure and sequence of a gene encoding the mouse small heat-shock protein, Hsp25, is presented and compared to the human hsp27. In contrast to the human hsp27, only two copies of hsp25 could be detected in the mouse genome. The intron-exon structure of the identified hsp25 is similar to the transcribed human hsp27, and the transcription start points of the genes are located at similar sites. The promoter region contains various putative transcription factor-binding elements including two G + C-rich Sp1-binding domains, two heat-shock elements, and an estrogen-responsive element half-site in direct proximity to the TATA box. These elements could explain hsp25 basal expression as well as its induction as a result of heat-shock and estrogen treatment.