Signaling iteractions in cytokinesis, cell wall biogenesis, and growth in fungi

描述（由申请人提供）：本申请的科学目标是1-了解连接胞质分裂、细胞壁生物发生和细胞生长中肌球蛋白II功能的信号相互作用2-了解肌球蛋白II功能与细胞壁完整性之间的关系3-确定抗真菌药物的新潜在靶点。我们将通过确定哪些代谢过程受到actomyosindependent和actomyosin independent突变的胞质分裂中断的影响，哪些信号传导通路是这些条件下细胞存活所必需的，以及在这些遗传突变体中连接这些通路的生化成分来实现这一点。肌球蛋白II缺陷的酿酒酵母细胞（myolA）表现出多种表型，具有胞质分裂和细胞壁突变体的特征。为了确定这些表型是否与基因表达的变化有关，我们确定了myol A菌株的全局转录谱。这些研究证实，PKC 1依赖的信号通路协调激活这些菌株中的细胞壁应激基因的转录。核糖体蛋白基因的协同下调也发生，并且观察到核糖体蛋白基因RPL 30和RPS 31的过表达部分恢复了myol A菌株中的细胞壁功能。我们的主要假设是，细胞壁应激基因的转录激活和核糖体蛋白基因在myol A菌株的下调分别代表细胞壁和胞质分裂突变体的不同表型，每个采用不同的相互关联的基本信号通路。为了检验这一假设，我们的具体目标是：1-对胞质分裂突变体chs 2A和细胞壁突变体fks 1A进行mRNA转录分析，以便随后与myolA菌株进行比较，2-对胞质分裂突变体中的mRNA翻译调节进行分析，3-确定胞质分裂突变株中PKC 1、TOR 1和TOR 2信号通路的状态并测试其对细胞活力的要求，和4-鉴定胞质分裂和细胞壁突变体中PKC 1和TOR信号通路的共同调节剂。这项研究的意义在于发现了新的调节连接，协调肌动球蛋白功能和真菌细胞壁的生物合成。这项研究也将增加我们对肌球蛋白II的丢失如何有助于酵母细胞的应激反应的理解。肌球蛋白II和应激信号之间的相互作用的知识可以导致新的抗真菌药物的潜在目标的识别。

DESCRIPTION (provided by applicant): The scientific goals of this application are to 1- understand signaling interactions connecting myosin II functions in cytokinesis, cell wall biogenesis, and cell growth 2- understand the relation between myosin II function and cell wall integrity and 3- identify new potential targets for antifungal drugs. We will accomplish this by identifying what metabolic processes are affected by the interruption of cytokinesis by actomyosindependent and actomyosin-independent mutations, what signaling pathways are necessary for cell survival under these conditions, and the biochemical components linking these pathways in these genetic mutants. Myosin ll-deficient Saccharomyces cerevisiae cells (myolA) exhibit multiple phenotypes with characteristics of both cytokinesis and cell wall mutants. To determine if these phenotypes were related to changes in gene expression, we determined the global transcription profile of myol A strains. These studies corroborated that the PKC1-dependent signaling pathway coordinately activates the transcription of cell wall stress genes in these strains. Coordinated down-regulation of ribosomal protein genes also occurs and it was observed that over expression of ribosomal protein genes RPL30 and RPS31 partially restored cell wall function in a myol A strain. Our main hypothesis is that transcriptional activation of cell wall stress genes and the down-regulation of ribosomal protein genes in myol A strains represent separate phenotypes for cell wall and cytokinesis mutants, respectively; each employing distinct essential signaling pathways that are interconnected. To test this hypothesis our specific aims are to: 1- conduct mRNA transcription analysis of the cytokinesis mutant chs2A and the cell wall mutant fksl A for subsequent comparison with myolA strains, 2-conduct analysis of mRNA translational regulation in cytokinesis mutants, 3- determine the status of the PKC1, TOR1, and TOR2 signaling pathways in cytokinesis mutant strains and test their requirement for cell viability, and 4- identify common regulators of the PKC1 and TOR signaling pathways in cytokinesis and cell wall mutants. The significance of this study lies in the discovery of new regulatory connections that coordinate actomyosin function and cell wall biogenesis in fungal cells. The proposed study will also increase our understanding about how loss of myosin II contributes to the stress response in yeast cells. Knowledge of the interaction between myosin II and stress signaling can lead to identification of potential targets for new antifungal drugs.