Modulation of Thermal Induction of hsp70 Expression by Ku Autoantigen or Its Individual Subunits
| Autor: | Honghai Ouyang, Dooha Kim, Gloria C. Li, Ligeng Li, André Nussenzweig, Paul Burgman, Shao-Hua Yang |
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| Rok vydání: | 1996 |
| Předmět: |
Hot Temperature
Time Factors Cell Survival Macromolecular Substances Protein subunit Molecular Sequence Data Gene Expression Biology Transfection Autoantigens Cell Line Heat Shock Transcription Factors Heat shock protein Animals Humans HSP70 Heat-Shock Proteins RNA Messenger Phosphorylation Heat shock HSF1 Ku Autoantigen Molecular Biology Transcription factor Base Sequence DNA Helicases Nuclear Proteins Antigens Nuclear Cell Biology Blotting Northern Molecular biology Recombinant Proteins Rats Hsp70 Ku Protein DNA-Binding Proteins Heat shock factor Kinetics Oligodeoxyribonucleotides Research Article Transcription Factors |
| Zdroj: | Molecular and Cellular Biology. 16:3799-3806 |
| ISSN: | 1098-5549 |
| DOI: | 10.1128/mcb.16.7.3799 |
| Popis: | Previously, we proposed a dual control mechanism for the regulation of the heat shock response in mammalian cells: a positive control mediated by the heat shock transcription factor HSF1 and a negative control mediated by the constitutive heat shock element-binding factor (CHBF). To study the physiological role of CHBF in the regulation of heat shock response, we purified CHBF to apparent homogeneity and showed it to be identical to the Ku autoantigen, a heterodimer consisting of 70-kDa (Ku-70) and 86-kDa (Ku-80) polypeptides. To study further the functional significance of Ku/CHBF in the cellular response to heat shock, we established rodent cell lines that stably and constitutively overexpressed one or both subunits of the human Ku protein, and examined the thermal induction of hsp70 and other heat shock proteins in these Ku-overexpressing ing cells. We show that expression of the human Ku-70 and Ku-80 subunits jointly or of the Ku-70 subunit alone specifically inhibits heat-induced hsp70 expression. Conversely, expression of human Ku-80 alone does not have this effect. Thermal induction of other heat shock proteins in all of the Ku-overexpressing cell lines appears not to be significantly affected, nor is the state of phosphorylation or the DNA-binding ability of HSF1 affected. These findings support a model in which hsp70 expression is controlled by a second regulatory factor in addition to the positive activation of HSF1. The Ku protein, specifically the Ku-70 subunit, is involved in the regulation of hsp70 gene expression. |
| Databáze: | OpenAIRE |
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