Combinatoial CREB/ATF dimers and cellular growth control

申请人描述：ATF/CREB/AP-1家族的蛋白质是 监测细胞内和细胞外的信号转导途径 条件并将这些信号传输到下游目标。一些家庭 成员（例如，vFos和vJun）是致癌的。ATF/CREB/AP-1蛋白质共有一个共同的 保守的bZIP结构域介导蛋白质二聚化和 序列特异性DNA结合活性。虽然bZIP域是高度 bZIP蛋白的某些组合彼此同源，形成二聚体， 而另一些则没有。此外，不同的bZIP二聚体具有显著的 区分密切相关的DNA结合位点的能力。这使得 一组有限的bZIP单体以形成异二聚体的库， 它可能调节一组特定基因的表达 一种特殊的生物反应。了解bZIP蛋白 二聚体可以形成、它们占据哪些DNA位点以及此类事件如何受到调节 将揭示细胞内稳态控制的基本方面和/或 分化裂殖酵母S. pombe提供了一个有吸引力的模型， 有机体进行这样的研究。我们已经证明，裂殖酵母的bZIP蛋白 在体内和体外形成组合二聚体。各种二聚体在 MAP激酶级联的控制和不同的二聚体引起不同的效应子 功能协调发展的因为S. pombe的基因组很小（约6,000个基因）， 测序项目已接近完成，人们可以识别和分析 大多数细胞bZIP蛋白。由于缺乏bZIP蛋白的突变体和 信号转导蛋白通常是有活力的，但也可能 揭示了上游调控和下游效应子功能。一 裂殖酵母bZIP蛋白二聚体的综合系统分析 本文提出目的1，阐明S.粟酒：确定 bZIP二聚体的成对组合关联，并鉴定DNA位点， 它们以高亲和力结合。目的2，揭示分子决定簇 组合二聚体形成和DNA结合：比较高分辨率 bZIP二聚体的结构单独和复合到它们的DNA位点。目标3： 进一步表征了由蛋白质介导的应激反应的调节机制， Mts1 bZIP蛋白：阐明MAP激酶Spcl在控制细胞凋亡中的作用。 Mts1的自身抑制功能。

APPLICANT'S DESCRIPTION: Proteins of the ATF/CREB/AP-1 family are components of signal transduction pathways that monitor intracellular and extracellular conditions and transmit those signals to downstream targets. Some family members (e.g., vFos and vJun) are oncogenic. ATF/CREB/AP-1 proteins share a conserved bZIP domain that mediates both protein dimerization and sequence-specific DNA binding activity. While the bZIP domains are highly homologous to one another, some combinations of bZIP proteins form dimers, while others do not. Furthermore, different bZIP dimers have the remarkable ability to discriminate between closely related DNA binding sites. This enables a limited set of bZIP monomers to form a repertoire of heterodimers, each of which presumably regulates the expression of a specific set of genes involved in a particular biological response. An understanding of which bZIP protein dimers can form, what DNA sites they occupy, and how such events are regulated will reveal fundamental aspects in the control of cellular homeostasis and/or differentiation. The fission yeast S. pombe provides an attractive model organism for such a study. We have shown that bZIP proteins of fission yeast form combinatorial dimers in vivo and in vitro. The various dimers are under control of a MAP kinase cascade and different dimers elicit distinct effector functions. Because S. pombe has a small genome (about 6,000 genes), and the sequencing project is nearly complete, one can identify and analyze the majority of cellular bZIP proteins. Since mutants lacking bZIP proteins and signal transduction proteins are generally viable, it is also possible to reveal both upstream regulatory and downstream effector functions. A comprehensive and systematic analysis of bZIP protein dimers of fission yeast is proposed. Aim 1, To elucidate the bZIP alphabet of S. pombe: determine pairwise combinatorial associations of bZIP dimers and identify DNA sites to which they bind with high affinity. Aim 2, To reveal molecular determinants of combinatorial dimer formation and DNA binding: compare high-resolution structures of bZIP dimers alone and complexed to their DNA sites. Aim 3, To further characterize regulatory mechanisms for stress responses mediated by the Mts1 bZIP protein: elucidate the role of the MAP kinase Spcl in controlling an autoinhibitory function of Mts1.