The Role of Snz and Sno Proteins in the Yeast Saccharomyces cerevisiae

Snz 和 Sno 蛋白在酿酒酵母中的作用

• 批准号: 9870878
• 负责人: Margaret Werner-Washburne
• 金额: $ 11万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9870878&HistoricalAwards=false
• 关键词: Role; Snz; Sno; Proteins; Yeast

The ability to regulate growth and division is recognized as one of the most important characteristics of living cells. However, in nature cells spend most of their time in a quiescent state or stationary phase, during which pathways that regulate non-growing, non-dividing cells become critical. Because most of a cell's life may be spent in a quiescent state, the ability to regulate entry into, survival during, and exit from this state is as important for species survival as the ability to divide. Although the quiescent state is of obvious significance, little is known about the mechanisms that allow cells to enter or exit this state or to survive for long periods of time, experiencing a variety of life-threatening stresses, including starvation. The long-term objective of this is to understand the molecular events that are important for the process of entry into, survival during, and exit from stationary phase, the quiescent state, in the yeast Saccharomyces cerevisiae. In prior research two novel genes, SNZ1 (SNooZe) and SNO1 (SNZ-proximal Open reading frame) that are induced in stationary phase were identified. SNZ and SNO genes are members of highly conserved gene families that are found in divergently transcribed pairs. Most yeast strains contain three SNZ/SNO gene pairs. Snz proteins are the most highly conserved proteins yet identified that are present in all three phylogenetic domains, i.e. the archaea, bacteria, and eucarya. The majority of this project focuses on SNZ1. In addition to its induction in stationary phase, SNZ1 is induced by specific amino acid, purine, and pyrimidine starvation. snzl mutants are also exquisitely sensitive to 6 azauracil, an inhibitor of the UTP and GTP biosynthetic pathways, and this sensitivity is suppressed by addition of uracil. These results suggest that Snzl protein, and probably also Sno 1 protein, is required for production of pyrimidine nucleotides, possibly through regulation of or involvement in a salvage pathway required in yeast during times of dire starvation.

调节生长和分裂的能力被认为是活细胞最重要的特征之一。然而，在自然界中，细胞大部分时间处于静止状态或静止期，在此期间，调节非生长、非分裂细胞的途径变得至关重要。因为细胞的大部分生命可能是在静止状态中度过的，所以调节进入、生存和退出这种状态的能力对物种的生存和分裂的能力一样重要。尽管静止状态具有明显的意义，但对于允许细胞进入或退出这种状态或长时间存活的机制知之甚少，经历各种危及生命的压力，包括饥饿。这项研究的长期目标是了解酵母进入、存活和退出静止阶段（静止状态）过程中重要的分子事件。在以往的研究中发现了两个新的基因SNZ1 （snoze）和SNO1 （SNZ-proximal Open reading frame）在固定期被诱导。SNZ和SNO基因是高度保守的基因家族成员，在不同的转录对中发现。大多数酵母菌株含有3对SNZ/SNO基因。Snz蛋白是目前发现的最高度保守的蛋白，存在于所有三个系统发育域，即古细菌、细菌和真核生物。这个项目主要关注SNZ1。除了在固定相诱导外，SNZ1还可以通过特定的氨基酸、嘌呤和嘧啶饥饿诱导。snzl突变体对6 azauracil（一种UTP和GTP生物合成途径的抑制剂）也非常敏感，这种敏感性可以通过添加尿嘧啶来抑制。这些结果表明，Snzl蛋白，也可能是Sno 1蛋白，是产生嘧啶核苷酸所必需的，可能是通过调节或参与酵母在极度饥饿时所需的救助途径。