Cell Wall Integrity Signaling in Yeast

酵母细胞壁完整性信号传导

• 批准号: 7912496
• 负责人: DAVID E. LEVIN
• 金额: $ 24.38万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-29 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7912496
• 关键词: Affect; Antifungal Agents; Binding; Biochemical; Biological Assay; Cell Wall; Cell surface; Cells; Chromatin; Complex; Cytolysis; Data; Defect; Development; Down-Regulation; Extracellular Domain; Family; G2/M Transition; Genes; Genetic; Genetic Transcription; Glucans; Growth; Homologous Gene; Human; MAP Kinase Modules; MEKs; Maintenance; Mediating; Mitogen-Activated Protein Kinases; Mitosis; Mitotic; Mitotic Checkpoint; Modeling; Molecular Genetics; Molecular Target; Monomeric GTP-Binding Proteins; Morphogenesis; Oxidative Stress; PH Domain; Pathway interactions; Patients; Phenotype; Phosphorylation; Phosphorylation Site; Phosphotransferases; Population; Process; Protein Kinase; Protein Kinase C; Proteins; Recruitment Activity; Regulation; Reporting; Role; Signal Pathway; Signal Transduction; Site; Stress; Temperature; Testing; Toxic effect; Transcriptional Activation; Yeasts; cell growth; extracellular; glucan synthase; loss of function; mutant; new therapeutic target; pathogen; promoter; response; sensor; spindle pole body; stem; transcription factor; yeast protein

There is a growing need for safe and effective antifungal agents that stems from the rapidly increasing population of immunecompromised patients. Because human cells do not possess the machinery needed to construct cell walls, the process of wall construction in fungal pathogens provides an attractive target for novel therapeutics. The long-term objective of this project is to understand how yeast cells maintain the structural integrity of their cell walls during growth and morphogenesis. These studies are likely to reveal suitable molecular targets for the development of antifungal agents that display selective toxicity against fungal cells. The principal mechanism by which yeast cells detect and respond to wall stress is a signaling pathway mediated by two families of cell surface sensors, a small GTPase (Rho1), protein kinase C (Pkc1), and a MAP kinase cascade, although additional pathways also contribute to the structural integrity of the wall. The specific aims of this project are 1) To determine if Pkc1 contributes to the G2/M transition by regulating the Mps1 protein kinase during spindle formation. Considerable evidence has accumulated to support a role for Pkc1 in mitosis. Our data implicates Pkc1 in the regulation of the Mps1 mitotic checkpoint kinase. We will test the hypothesis that Mps1 is a Pkc1 target and explore the mitotic effects of this phosphorylation. 2) To determine if Mpk1 acts as a transcription factor under conditions of cell wall stress. We have exciting evidence revealing that the Mpk1 MAP kinase can regulate the SBF transcription factor in a manner that is independent of its protein kinase activity. We propose to test the unusual notion that Mpk1 forms a ternary complex with SBF on the DMA,and to explore the mechanism by which Mpk1 drives transcription. 3) To determine if the Wsc1 sensor is recruited to the site of polarized growth through a /ff-1,3- glucan-binding domain. The extracellular region of Wsc1 possesses a cys-rich domain that we propose binds to glucan chains and is responsible for localization of Wsc1 to the glucan synthase. We will test this model by a combination of biochemical and molecular genetic approaches. 4) To understand how the PH domain proteins, AsklO and Ypr115w, contribute to the maintenance of cell wall integrity. We have identified two redundant proteins whose loss of function results in cell lysis. We propose a multifaceted approach to establishing their role in the maintenance of cell wall integrity.

由于抗真菌药物的快速增加，对安全有效的抗真菌药物的需求日益增长。 免疫力低下的患者。因为人类细胞不具备 构建细胞壁，在真菌病原体中的壁构建过程提供了一个有吸引力的目标， 新疗法。该项目的长期目标是了解酵母细胞如何维持 它们的细胞壁在生长和形态发生过程中的结构完整性。这些研究可能会揭示 用于开发抗真菌剂的合适的分子靶点， 真菌细胞酵母细胞检测和响应壁应力的主要机制是信号传导 由两个家族的细胞表面传感器介导的途径，一个小的GT3（Rho 1），蛋白激酶C（Pkc 1）， 和MAP激酶级联，尽管其他途径也有助于结构完整性的 墙本项目的具体目标是：1）通过以下方式确定Pkc 1是否有助于G2/M过渡 在纺锤体形成过程中调节Mps 1蛋白激酶。大量证据表明， 支持PKC 1在有丝分裂中作用。我们的数据暗示Pkc 1在Mps 1有丝分裂检查点的调节 激酶。我们将检验Mps 1是Pkc 1靶点的假设，并探讨其对有丝分裂的影响。 磷酸化2)确定Mpk 1在细胞壁应激条件下是否作为转录因子发挥作用。 我们有令人兴奋的证据表明，Mpk 1 MAP激酶可以调节SBF转录因子， 这种方式与其蛋白激酶活性无关。我们建议测试这个不寻常的概念，即Mpk 1 在DMA上与SBF形成三元复合物，并探索Mpk 1驱动的机制 转录。3)为了确定Wsc 1传感器是否通过a /ff-1，3- 葡聚糖结合域。Wsc 1的胞外区具有一个富含cys的结构域， 与葡聚糖链结合并负责Wsc 1定位于葡聚糖合酶。我们将测试这个 通过生物化学和分子遗传学方法的组合建立模型。4)了解PH值是如何 结构域蛋白Ask 10和Ypr 115 w有助于维持细胞壁的完整性。我们已经确定 两种冗余蛋白质，其功能丧失导致细胞溶解。我们建议采取多方面的办法， 从而确定它们在维持细胞壁完整性中的作用。