金屬感應轉錄因子 (MTF-1) 是一具六個C2H2鋅指區之轉錄蛋白，當遭受金屬、氧化物及高溫等壓力刺激時，細胞內的MTF-1即被活化並進入核中與特定之核酸序列 (MRE) 結合，進而調控MT等下游基因的表現。然而直至目前為止，MTF-1如何與其他因子相互合作以影響下游基因表達之確切分子機制，尚未被闡明。在本篇研究中，我們發現純化的小鼠MTF-1失去與MRE相結合的能力，即使以鋅處理亦然，但加入細胞萃取液後即可回復其結合能力，推測細胞中具有可促使兩者結合之因子。我們進行各項實驗來了解此因子之特性，並以離子交換樹脂及凝膠管柱層析試著將可能之因子由細胞萃取液中分離出來。由實驗結果得知此因子分布在真核細胞之核與質內，且亦存在於原核生物中。不論MTF-1是否進行轉譯後修飾皆可受此因子活化。若外加具調節子活性之熱休克蛋白即可使純化的MTF-1與MRE結合，推測此因子是藉由穩定小鼠MTF-1的結構來達到加強其與MRE結合的目的。然而我們發現亦有其他種類的蛋白質同樣具有增進MTF-1與MRE結合的效果，因此，此因子調控MTF-1結合能力之機制仍需更進一步的研究探討。

Metal-responsive transcription factor-1 (MTF-1) is a transcription factor contains six C2H2 type zinc finger motifs. When cells are exposed to stresses, such as metal and oxidative stress, MTF-1 can be activated and translocates into nuclei. The factor will bind to metal response elements (MREs) and induces gene expressions. We investigated in this study how MTF-1 interacts with MREs. Notably, purified MTF-1 lost its ability to bind MRE even in the presence of Zn. However, addition of cell extract restored the DNA binding activity of MTF-1. We hypothesized that there are factors in cell extract participating in MTF-1 binding reaction. In this study, we attempted to purify and characterize this factor using ion-exchange and gel filtration chromatographies. Our results showed that this factor exists in the nuclei and cytoplasm of eukaryotic cells, and it can also be found in prokaryotic cells. Addition of chaperons, such as Hsp90 and Hsc70 exert the binding ability of MTF-1, raising the possibility that this factor facilitates MTF-1 binding by stabilizing its structure. A variety of proteins have been used to classify the characteristics of the potential MTF-1 binding factor. However, no conclusive result was obtained.

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