Zinc-dependent regulation of gene expression

说明(申请人提供)：锌是一种金属元素，对生命是必不可少的，但过量时是有毒的。因此，细胞依赖于维持相对恒定的细胞内锌水平的机制，尽管细胞外介质波动。为了确保锌水平维持在细胞新陈代谢的最佳水平，锌运输或锌储存所必需的基因的表达通常取决于细胞锌水平。虽然基因表达的这种变化是锌稳态的核心，但感受细胞内锌水平并调节这些变化的因素的一致性在很大程度上尚不清楚。我们研究的长期目标是了解真核细胞如何感知和调节细胞内锌水平。为了识别感知锌的蛋白质，我们利用了裂殖酵母多才多艺的遗传学。使用这个模型系统，我们已经分离出一种新的因子，它是锌依赖的基因表达调控所必需的。该因子命名为Loz1，含有一个双C2H2型锌指结构域，对于锌依赖的基因表达调控是必不可少的。这项建议描述了一种分子、遗传和生物化学相结合的方法来确定锌是如何调控Loz1的。具体地说，我们将解决Loz1是否直接感知锌水平，以及这是否需要双C2H2型锌指结构域。

DESCRIPTION (provided by applicant): Zinc is a metal element that is essential for life, but is toxic when present in excess. Cells therefore rely on mechanisms to maintain a relatively constant intracellular level of zinc despite fluctuations in the extracellular medium. To ensure that zinc levels are maintained at an optimal level for cell metabolism, the expression of genes necessary for zinc transport or zinc storage is often dependent upon cellular zinc levels. Although such changes in gene expression are central to zinc homeostasis, the identity of the factors that sense intracellular zinc levels and mediate these changes is largely unknown. The long-term goal of our research is to understand how eukaryotic cells sense and regulate intracellular zinc levels. To identify proteins that sense zinc, we have taken advantage of the versatile genetics of Schizosaccharomyces pombe. Using this model system we have isolated a novel factor that is required for zinc-dependent regulation of gene expression. This factor, designated Loz1, contains a double C2H2-type zinc finger domain that is essential for zinc-dependent regulation of gene expression. This proposal describes a combined molecular, genetic and biochemical approach to determine how Loz1 is regulated by zinc. Specifically, we will address whether Loz1 directly senses zinc levels, and whether this requires the double C2H2-type zinc finger domain.