Abstract |
While sequencing the first intron of the rat heat shock protein 27 gene (hsp27), we identified a consensus heat shock regulatory element (HSE). This intronic HSE (i-HSE) is conserved among mammalian hsp27 genes. The aim of this study was to investigate possible effects of this intronic HSE (i-HSE) on transcription from the rat hsp27 promoter. Gel mobility shift assays indicated that the i-HSE bound heat shock transcription factor 1 (HSF1) in a manner equivalent to that of HSE present in hsp27 promoter (p-HSE). The effect of i-HSE on transcription from the hsp27 promoter was evaluated using reporter constructs transiently transfected in the osteosarcoma cell line ROS17/2.8. When inserted 5' to a 145 bp fragment of the hsp27 promoter not containing p-HSE, a 215 bp fragment of hsp27 intron 1 containing i-HSE enhanced CAT activity and conferred heat shock-inducible activity to the construct. This intronic fragment containing i-HSE also enhanced CAT activity in either normal or heat-shocked culture conditions when inserted 3' to the CAT open reading frame. However, in chimeric reporter constructs with a 273 bp hsp27 promoter containing p-HSE directly 5' to CAT reporter, and with a 215 bp fragment containing i-HSE inserted 3' to the CAT open reading frame, transcription from hsp27 promoter was reduced under normal and heat-stressed culture conditions. Mutation of the i-HSE reversed this effect. Further study is required to define the mechanism by which the i-HSE-containing region of the hsp27 promoter may mediate negative regulation of hsp27 transcription.
|
Authors | L F Cooper, K Uoshima, Z Guo |
Journal | Biochimica et biophysica acta
(Biochim Biophys Acta)
Vol. 1490
Issue 3
Pg. 348-54
(Feb 29 2000)
ISSN: 0006-3002 [Print] Netherlands |
PMID | 10684980
(Publication Type: Comparative Study, Journal Article)
|
Chemical References |
- HSP27 Heat-Shock Proteins
- Heat-Shock Proteins
- Hspb1 protein, rat
- Neoplasm Proteins
- Nuclear Proteins
|
Topics |
- Animals
- Cell Line
- Genes, Reporter
- HSP27 Heat-Shock Proteins
- Heat-Shock Proteins
(genetics, metabolism)
- Introns
- Neoplasm Proteins
(genetics)
- Nuclear Proteins
(metabolism)
- Promoter Regions, Genetic
- Rats
- Restriction Mapping
- Temperature
- Transcription, Genetic
- Transfection
|