Zhong M, Orosz A, Wu C
Laboratory of Molecular Cell Biology, National Cancer Institute, Bethesda, Maryland 20892-4255, USA.
Mol Cell. 1998 Jul;2(1):101-8. doi: 10.1016/s1097-2765(00)80118-5.
The heat shock transcription factor HSF activates expression of its target genes in response to elevated temperatures and chemical or physiological stress. A key step in the activation process involves the formation of HSF homotrimers, leading to high-affinity DNA binding. The mechanism by which HSF trimerization and DNA binding is regulated by stress signals has remained elusive. Here, we report that trimerization and DNA binding of purified Drosophila HSF can be directly and reversibly induced in vitro by heat shock temperatures in the physiological range and by an oxidant, hydrogen peroxide. Other inducers of the heat shock response, including salicylate, dinitrophenol, ethanol, and arsenite, have no effect on HSF trimerization in vitro, indicating that these inducers act by indirect mechanisms.
热休克转录因子HSF在温度升高、化学或生理应激时激活其靶基因的表达。激活过程中的关键步骤涉及HSF同三聚体的形成，从而实现高亲和力的DNA结合。应激信号调控HSF三聚化和DNA结合的机制一直不清楚。在此，我们报告纯化的果蝇HSF的三聚化和DNA结合在体外可被生理范围内的热休克温度和氧化剂过氧化氢直接且可逆地诱导。热休克反应的其他诱导剂，包括水杨酸盐、二硝基苯酚、乙醇和亚砷酸盐，在体外对HSF三聚化没有影响，表明这些诱导剂通过间接机制起作用。
