MECHANISMS OF YEAST TRANSCRIPTIONAL REGULATORS

这项工作的长期目标是从精确的分子角度来理解 , 酵母转录抑制因子α 2是如何关闭 两组细胞类型特异性基因。 这种蛋白质总是以组合方式发挥作用 n 与另外两种蛋白质中的一种 在α细胞中，它与 GRM蛋白;在α/α细胞中，它与α 1蛋白作用。 这些访问者 蛋白质导向子α 2与两种不同类型的操纵子结合， α 2关闭两组不同基因的表达。三种规格 C 该提案所涉及的问题如下：（1）如何 调节蛋白共同作用？ (2)他们如何重新洗牌， 不同的监管活动？ (3)一旦绑定到其操作符， α 2执行其靶基因的抑制。 基本的方法是利用简单的生化和遗传学的结果 构建和测试分子模型的实验。 一个立即 例如，实验目标是重建和研究 仅使用纯化的蛋白质的调节剂的不同成对组合。 第二种实验方法是重建转录水平。 在体外通过α 2的抑制和在体外的步骤的测定， 被α 2阻断的转录。 对α 2的拟议研究应该提供一个详细的分子图像 显示了在简单的真核生物中细胞特化是如何维持的。 啤酒。 考虑到α 2与细胞类型调节因子的相似性， 更高的生物，很可能是许多原则发展为 Alpha 2将适用于其他设置。 对分子的基本理解 R 细胞特化背后的事件对于理解细胞特化是如何发生的至关重要。 过程可能会失败，这种情况可能会导致许多不同的 病理状态。

The long-term goal of this work is to understand, in precise molecular term , how the yeast transcriptional repressor alpha 2 turns off transcription of two set of cell-type specific genes. This protein always acts in combinati n with one of two additional proteins. In alpha cells it cooperates with the GRM protein; in a/alpha cells, it acts with the al protein. These accessor proteins director alpha 2 to two different types of operator and thus enabl alpha 2 to turn off expression of two different sets of genes. Three specif c questions addressed by the proposal are as follows: (1) How do these regulatory proteins act together? (2) How do they reshuffle to create different regulatory activities? (3) How, once bound to its operators, doe alpha 2 carry out repression of its target genes. The basic approach is to use results of simple biochemical and genetic experiments to construct and test molecular models. ONe immediate experimental goal, for example, is a reconstruction and study of the different pairwise combinations of regulators using only purified proteins. A second experimental approach is a reconstruction of transcriptional repression by alpha 2 in vitro and a determination of the step in transcription that is blocked by the action of alpha 2. The proposed studies of alpha 2 should provide a detailed molecular picture showing how cell specialization is maintained in a simple eukaryote, S. cerevisiae. Given the similarity of alpha 2 to cell-type regulators in higher organisms, it is likely that many of the principles developed for alpha 2 will apply in other settings. A basic understanding of the molecul r events underlying cell specialization is essential for understanding how th process can fail, a condition that can give rise to a number of different pathological states.