Structure and Functions of small heat shock proteins

应激反应刺激细胞防御机制的启动，包括热休克蛋白(HSPs)基因的大量上调。小分子热休克蛋白(SHSPs)是一种分子伴侣蛋白，它被动地结合底物，形成错误折叠的蛋白质库，这些蛋白质最终会被依赖于ATP的伴侣蛋白折叠或被蛋白酶体降解。它们对底物的亲和力受到细胞条件的严格控制。最近的研究表明，sHSPs还可以在不同水平上发挥其他生理作用，如调节细胞凋亡，但sHSPs执行这些功能的机制仍存在争议。

The stress response stimulates the onset of the cell-defence machinery including the massive up-regulation of heat shock protein (Hsps) genes. Small Hsps (sHsps) are molecular chaperones that passively bind their substrate to form reservoirs of misfolded proteins that will ultimately be refolded by ATP-dependent chaperones or degraded by the proteasome. Their affinity for substrates is tightly regulated by cellular conditions. Recent studies have shown that sHsps can also play other physiological roles such as regulating apoptosis at various levels, but the mechanisms by which sHsps perform these functions are still debated.