Abstract
Under heat, heavy metal, and viruses conditions, chaperons increase and stablize proteins in the cells. These chaperons are so-called heat shock proteins. The heat shock protein families consist of HSP110, HSP90, HSP70, and small HSPs. Two forms of mice HSP90, i.e. HSP84 and HSP86, share 86% identity in protein sequences and 76% identity in cDNA sequences. In mice cells, HSP84 and HSP86 response to stress differently.We treated 9L rat brain tumor cell line with cadmium chloride, the newly synthesized amount of HSP86 is much more than that of HSP84 in [35S]methionine labeling experiment. The published rat hsp90 cDNA was assigned to be hsp84 group through cross-species sequence comparison. To search for the missing counterpart of rat hsp86 cDNA, homologous cloning method employing mice homologous RT-PCR primers was used to get the first probe for rat hsp86. The RT-PCR probe was used in the screening for rat hsp86 genomic cosmid library. Several positive clones containing hsp86 and the promoter region have been obtained of which a 1411 bp of putative rat hsp86 promoter region, a 641 bp of 5'-untranslated region and a 603 bp of coding region have been identified. According to the sequence alignment with the promoter region of mice hsp86, five conserved regions in rat hsp86 promoter were found to show more than 85% identity to the mice homologues. Within them TATA, GC box, and most importantly heat shock element (HSE) were identified in corresponding positions, suggesting that the essential transcription characteristics of mice and rat hsp86s are intact, and the cloned region might contain a functional promoter. Further investigation on the regulation of promoter activity and transcription will continue base on the information obtained in this thesis.