Cano-Gauci D F, Sarkar B
Department of Biochemistry Research, The Hospital for Sick Children, Toronto, Canada.
FEBS Lett. 1996 May 13;386(1):1-4. doi: 10.1016/0014-5793(96)00356-0.
We report here the first demonstration that reversible metal exchange occurs between metallothionein (MT) and full-length estrogen receptor (ER). Specific binding of ER to estrogen response element is inhibited in the presence of 40 microM thionein and restored by 120 microM zinc. Moreover, ER in metal-depleted nuclear extracts exhibits reduced DNA binding which can be restored by 140 microM native MT. Hence, thionein inhibits DNA binding by abstracting zinc from functional ER while native MT is capable of restoring binding to metal-depleted extracts by donating metal to ER. This indicates MT may be an important physiological regulator of intracellular zinc and/or other metals.
我们在此报告首次证明金属硫蛋白（MT）与全长雌激素受体（ER）之间发生可逆的金属交换。在存在40微摩尔硫蛋白的情况下，ER与雌激素反应元件的特异性结合受到抑制，并通过120微摩尔锌得以恢复。此外，金属耗尽的核提取物中的ER表现出DNA结合能力降低，而140微摩尔天然MT可使其恢复。因此，硫蛋白通过从功能性ER中提取锌来抑制DNA结合，而天然MT能够通过向ER提供金属来恢复与金属耗尽提取物的结合。这表明MT可能是细胞内锌和/或其他金属的重要生理调节剂。
