An Intercellular Connection in Endospore Development

内生孢子发育中的细胞间连接

基本信息

批准号：
8669557
负责人：
Charles P. Moran
金额：
$ 29.64万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-05-01 至 2018-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8669557
关键词：
Address Amino Acid Substitution Antibiotic Resistance Antibiotics Appearance Bacillus anthracis Bacillus cereus Bacillus subtilis Bacteria Bacterial Infections Biological Models Cell Differentiation process Cell Membrane Proteins Cell membrane Cells Cellular biology Chemicals Clostridium difficile Communication Complex Cytoplasm DNA-Directed RNA Polymerase Development Disinfectants Employee Strikes Environment Figs - dietary Fluorescence Resonance Energy Transfer Gene Expression Gene Expression Regulation Genes Goals Health Host Defense Human Knowledge Location Membrane Mission Modeling Molecular Mothers Multiprotein Complexes Mutagenesis N-Acetylmuramoyl-L-alanine Amidase Proteins Public Health Recruitment Activity Reproduction spores Research Resistance Role Siblings Sigma Factor Signal Transduction Specificity Staging Structural Models System Testing Transducers combat crosslink design improved in vivo intercellular connection intracellular protein transport novel novel strategies pathogen promoter protein complex public health relevance

项目摘要

DESCRIPTION (provided by applicant): Many bacteria build specialized differentiated cells in order to survive environmental insults, to disseminate in the environment, and to resist host defenses, antibiotics and disinfectants. A striking example of this type of cell differentiation by many important bacterial pathogens is the formation of endospores (e.g., Bacillus anthracis, Bacillus cereus, Clostridium difficile). Our overall goal is to understand the special molecular mechanisms that guide the development of endospores in order to identify novel targets for disrupting spore development. We will exploit the model system of endospore development in Bacillus subtilis because this system is amenable to analysis and its study has led to the discovery of many mechanisms that control gene expression in most bacteria, including pathogens. In this proposal we focus on the roles of a protein complex that connects two cells during endospore development. Early after the onset of endospore formation the cell divides asymmetrically giving rise to two dissimilar sibling cells. One of these cells (the forespore) develops into the endospore, while the other (the mother cell) becomes a terminally differentiated cell that nurtures the developing endospore. Remarkably, gene expression is coordinated between the forespore and mother cell (e.g., expression of specific genes in the mother cell is required before a subsequent set of genes is expressed in the forespore). The communication between the mother cell and forespore depends upon the targeting of several groups of proteins to the interface between the mother cell and forespore. The mechanisms for subcellular localization of specific proteins are of fundamental importance in cell biology and development. The central questions to be addressed in this proposal are how are specific proteins localized to the interface between the mother cell and forespore, and what are their functions. The two key proteins in this study, SpoIIQ and SpoIIIAH, interact through two membranes to connect the forespore and the mother cell. The SpoIIQ-SpoIIIAH complex serves as the founder that marks the membrane interface between the forespore and mother cell for the recruitment of other proteins to this subcellular location, including peptidoglycan hydrolases that function during the phagocytic-like engulfment of the forespore membrane by the mother cell membrane, proteins required for signaling from the forespore to the activate mother cell gene expression, and mother-cell proteins required for gene expression in the forespore. Moreover, the SpoIIQ-SpoIIIAH complex appears to form a new type of channel or transporter that connects the mother cell and forespore cytoplasms. The specific aims of this proposal are designed to identify which and how other proteins are recruited to this intercellular connection, and how these protein complexes function to coordinate gene expression between the two cells.

描述（由申请人提供）：许多细菌构建专门的分化细胞，以便在环境侵害中生存、在环境中传播以及抵抗宿主防御、抗生素和消毒剂。这种细胞分化的一个引人注目的例子是许多重要的细菌病原体是内生孢子的形成（例如炭疽芽孢杆菌、蜡样芽孢杆菌、艰难梭菌）。我们的总体目标是了解指导内生孢子发育的特殊分子机制，以便确定破坏孢子发育的新靶点。我们将利用枯草芽孢杆菌内生孢子发育的模型系统，因为该系统易于分析，并且其研究已发现许多控制大多数细菌（包括病原体）基因表达的机制。在本提案中，我们重点关注在内生孢子发育过程中连接两个细胞的蛋白质复合物的作用。内生孢子形成开始后不久，细胞不对称分裂，产生两个不同的兄弟细胞。其中一个细胞（前孢子）发育成内生孢子，而另一个（母细胞）则成为终末分化细胞，培育发育中的内生孢子。值得注意的是，基因表达在前孢子和母细胞之间协调（例如，在前孢子中表达后续基因组之前，需要在母细胞中表达特定基因）。母细胞和前孢子之间的通讯取决于几组蛋白质靶向母细胞和前孢子之间的界面。特定蛋白质的亚细胞定位机制在细胞生物学和发育中至关重要。该提案要解决的核心问题是特定蛋白质如何定位于母细胞和前孢子之间的界面，以及它们的功能是什么。本研究中的两个关键蛋白 SpoIIQ 和 SpoIIIAH 通过两个膜相互作用，连接前孢子和母细胞。 SpoIIQ-SpoIIIAH 复合物作为标记前孢子和母细胞之间膜界面的基础，用于将其他蛋白质招募到该亚细胞位置，包括在母细胞吞噬前孢子膜过程中发挥作用的肽聚糖水解酶膜、从前孢到激活母细胞基因表达的信号传导所需的蛋白质以及前孢中基因表达所需的母细胞蛋白质。此外，SpoIIQ-SpoIIIAH 复合物似乎形成了一种连接母细胞和前孢子细胞质的新型通道或转运蛋白。该提案的具体目标是确定哪些蛋白质以及如何招募其他蛋白质到这种细胞间连接，以及这些蛋白质复合物如何发挥作用来协调两个细胞之间的基因表达。