EUKARYOTIC GENE REGULATION AND FUNCTION--THE METALLOTHIONEIN SYSTEM

金属离子的转录调控为研究提供了一个有用的范例 真核基因调控。当酵母细胞暴露在铜中时，它们 抑制细胞表面还原酶基因转录并激活 金属硫蛋白基因的转录。还原酶催化 铜(II)转化为铜(I)，这是本实验室发现的一个新反应。 而金属硫蛋白则与铜发生螯合作用，参与解毒作用。 主要的细胞表面还原酶由FRE1编码，它以前是 被鉴定为铁还原酶，而另一种形式在 Upc31突变株。金属硫蛋白基因的主要调控因子 转录是ACEI，它包含一种新颖的“铜拳”结构 以多核铜(I)-S簇合物为基础。第二条调控途径是 由一种热休克转录因子控制。三种蛋白质 调控哺乳动物金属硫蛋白基因转录的研究进展 目前正在从分子水平对其进行鉴定和表征。

Transcriptional control by metal ions provides a useful paradigm to study eukaryotic gene regulation. When yeast cells are exposed to Cu, they repress transcription of the gene for cell surface reductase and activate transcription of the gene for metallothionein. Reductase catalyzes the conversion of Cu(II) to Cu(I), a new reaction discovered in this lab, whereas metallothionein chelates Cu and is involved in detoxification. The major cell surface reductase is encoded by FRE1, which was previously identified as an Fe reductase, while an alternative form is revealed in upc3l mutant strains. The major regulator of metallothionein gene transcription is ACEI, which contains a novel "copper fist" structure based on a polynuclear Cu(I)-S cluster. A second regulatory pathway is controlled by a heat shock transcription factor. Three proteins that regulate metallothionein gene transcription in mammals have been identified and are being characterized at the molecular level.