CAREER: The Role of The Escherichia Coli Alternative Sigma Factor, Sigma(E), In Cell Envelope Homeostasis

革兰氏阴性菌的细胞包膜是一个复杂的、动态的隔室，对细胞的存活至关重要。它提供了细胞与周围环境之间的屏障，确保了结构的完整性，并决定了细胞的形态。细胞包膜是许多动态过程的场所，包括溶质、蛋白质和营养物质的运输，许多细胞大分子的生物合成和能量的产生。此外，细胞包膜可以在温度变化和营养物质匮乏等胁迫下进行重塑，并随着细胞周期的进展而不断生长和变化。在细菌中，协调细胞包膜过程并在细胞质和细胞包膜之间传递信息以维持细胞稳态的信号转导途径和相应的反应尚不完全清楚。在大肠杆菌中，感知细胞包膜完整性的关键途径之一是由替代sigma因子（s E）控制的，该因子主要以其在细胞包膜应激过程中的作用为特征。s E是一种必需基因，表明s E在应激反应之外的作用。为什么这种基因是生存能力所必需的原因尚不清楚。该项目的目的是阐明s E在非应激细胞中维持细胞包膜完整性中的作用，以及协调s E活性与细胞中其他调节事件的调节途径。该项目还包括教育和公共宣传部分，重点是教育该领域的本科生和研究生，培养未来的科学教师，并向公众通报有关微生物学的当前问题。

The cell envelope of Gram-negative bacteria is a complex, dynamic compartment that is crucial for the survival of the cell. It provides a barrier between the cell and the surrounding milieu, ensures the structural integrity, and determines the morphology of the cell. The cell envelope is the site of many dynamic processes including solute, protein and nutrient transport, biosynthesis of many cellular macromolecules, and energy generation. In addition, the cell envelope can be remodeled in response to stresses such as changes in temperature and scarcity of nutrients, and is continually growing and changing as a result of cell cycle progression. The signal transduction pathways and corresponding responses that coordinate cell envelope processes and communicate information between the cytoplasm and cell envelope to maintain cellular homeostasis in bacteria are not fully understood. In Escherichia coli, one of the key pathways that senses the integrity of the cell envelope is controlled by the alternative sigma factor, s E , which has primarily been characterized for its role during cell envelope stress. s E is an essential gene, suggesting a role for s E beyond the stress response. The reason why this gene is required for viability is not known. The objectives of this project are to elucidate the role of s E in maintaining cell envelope integrity in unstressed cells and the regulatory pathways that coordinate s E activity with other regulatory events in the cell. This project also contains educational and public outreach components that focus on educating undergraduates and graduate students in the field, educating future science teachers, and informing the general public about current issues concerning microbiology.