Rine J
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3202, USA.
Mol Cell Biol. 2001 Oct;21(19):6395-405. doi: 10.1128/MCB.21.19.6395-6405.2001.
Sterol levels affect the expression of many genes in yeast and humans. We found that the paralogous transcription factors Upc2p and Ecm22p of yeast were sterol regulatory element (SRE) binding proteins (SREBPs) responsible for regulating transcription of the sterol biosynthetic genes ERG2 and ERG3. We defined a 7-bp SRE common to these and other genes, including many genes involved in sterol biosynthesis. Upc2p and Ecm22p activated ERG2 expression by binding directly to this element in the ERG2 promoter. Upc2p and Ecm22p may thereby coordinately regulate genes involved in sterol homeostasis in yeast. Ecm22p and Upc2p are members of the fungus-specific Zn[2]-Cys[6] binuclear cluster family of transcription factors and share no homology to the analogous proteins, SREBPs, that are responsible for transcriptional regulation by sterols in humans. These results suggest that Saccharomyces cerevisiae and human cells regulate sterol synthesis by different mechanisms.
甾醇水平影响酵母和人类中许多基因的表达。我们发现酵母的同源转录因子Upc2p和Ecm22p是甾醇调节元件（SRE）结合蛋白（SREBP），负责调节甾醇生物合成基因ERG2和ERG3的转录。我们确定了一个7碱基对的SRE，它存在于这些基因和其他基因中，包括许多参与甾醇生物合成的基因。Upc2p和Ecm22p通过直接结合ERG2启动子中的这一元件来激活ERG2的表达。Upc2p和Ecm22p可能由此协同调节酵母中参与甾醇稳态的基因。Ecm22p和Upc2p是真菌特有的Zn[2]-Cys[6]双核簇转录因子家族的成员，与负责人类甾醇转录调控的类似蛋白SREBP没有同源性。这些结果表明酿酒酵母和人类细胞通过不同的机制调节甾醇合成。
