[Studies on the transcription regulation by upstream sequence of human heat shock protein 90 beta gene]

Using a pair of synthetic oligonucleotide as primers, human peripheral lymphocyte lambda GEM-11 genomic DNA library as template, a fragment spanning -1102/+68bp of human heat shock protein 90 beta gene was amplified by polymerase chain reaction (PCR) and cloned into pGEM-4Z vector. The cloned fragment was truncated and ligated to an eukaryotic expression vector containing luciferase as a reporter gene. These subclones were transfected into Jurkat cells and the cellular luciferase activity and mRNA level were measured under either heat shock or PHA activation. Our results suggest that: (1) 5' flanking sequences of hsp90 beta mediates a relatively higher basal level expression via promotor region; (2) under heat shock, presence of the fragment surprisingly reduced luciferase activity, a heat shock induced negative regulatory element was restricted to -554/-171bp; and (3) PHA activation requires distal 5' sequence.