Activation of the chaperone Hsp26 is controlled by the rearrangement of its thermosensor domain
Activation of the chaperone Hsp26 is controlled by the rearrangement of its thermosensor domain
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DOI：
10.1016/j.molcel.2007.11.025
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发表时间：
2008-02-01
期刊：
影响因子：
16
通讯作者：
Buchner, Johannes
中科院分区：
文献类型：
--
作者：
Franzmann, Titus M.;Menhorn, Petra;Buchner, Johannes
细胞通过转录一组特殊的基因来应对温度的突然升高，这种现象被称为热休克反应。在酿酒酵母中，分子伴侣Hsp26是热休克反应的一个组成部分。HSP26具有显著的直接感知温度升高的能力，可以从不活跃状态切换到伴侣活跃状态。这种温度调节的基本原理一直是个谜。具有改变光谱性质的HSP26变体使我们能够确定控制这一激活过程的结构元件。我们发现，HSP26的温度传感是其中间结构域在较窄的温度范围内改变其构象的特征。这种结构重排允许Hsp26通过可逆地释放其伴侣活性来自主和直接地对热应激做出反应。因此，Hsp26中间结构域是一个温度传感器和伴侣活性的内在调节因子。
Cells respond to a sudden increase in temperature with the transcription of a special set of genes, a phenomenon known as the heat shock response. In the yeast S. cerevisiae, the molecular chaperone Hsp26 is one component of the heat shock response. Hsp26 has the remarkable ability to sense increases in temperature directly and can switch from an inactive to a chaperone-active state. The underlying principle of this temperature regulation has remained enigmatic. Hsp26 variants with altered spectroscopic properties allowed us to identify structural elements controlling this activation process. We show that temperature sensing by Hsp26 is a feature of its middle domain that changes its conformation within a narrow temperature range. This structural rearrangement allows Hsp26 to respond autonomously and directly to heat stress by reversibly unleashing its chaperone activity. Thus, the Hsp26 middle domain is a thermosensor and intrinsic regulator of chaperone activity.