The cellular filopodia mechanism in Shigella membrane protrusion formation

志贺氏菌膜突起形成的细胞丝状伪足机制

• 批准号: 8607891
• 负责人: Marcia B Goldberg
• 金额: $ 21.69万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8607891
• 关键词: Actins; Bacteria; Cell Surface Extensions; Cell membrane; Cell physiology; Cells; Cellular Membrane; Cessation of life; Colorectal; Complex; Cytolysis; Cytoskeleton; Data; Diarrhea; Disease; Dysentery; Endocytosis; Enteral; Environment; Epithelial Cells; Epithelium; Escherichia coli EHEC; Family; Filament; Filopodia; Generations; Gray unit of radiation dose; Homologous Gene; Human; Human Cell Line; Infection; Insulin Receptor; Intestines; Investigation; Lead; Link; Membrane; Molecular; Movement; Neoplasm Metastasis; Organism; Pathogenesis; Pathway interactions; Phosphorylation; Phosphotransferases; Plasma; Play; Process; Proteins; Recruitment Activity; Role; Shapes; Shigella; Shigella flexneri; Signaling Molecule; Signaling Protein; Source; Tail; Tertiary Protein Structure; Testing; Tissues; Vacuole; amphiphysin; base; cell motility; design; dimer; human tissue; improved; insight; intestinal epithelium; link protein; member; monolayer; pathogen; polymerization; public health relevance; uptake; vasodilator-stimulated phosphoprotein

DESCRIPTION (provided by applicant): Shigella are intracellular enteric human pathogens that move to the cell periphery via actin-based motility, whereupon they generate protrusions of the plasma membrane that penetrate into and are taken up by adjacent uninfected cells. The generation of plasma membrane protrusions is critical for Shigella spread, but the mechanisms involved are poorly understood. We have shown that cellular diaphanous formins and IRTKS are each required for both efficient formation of plasma membrane protrusions and efficient spread of Shigella through cell monolayers. Both diaphanous formins and the IRTKS homolog IRSp53 are components of the cellular fiolopodia tip complex and both are required for efficient formation of filopodia. IRTKS and IRSp53 are I-BAR domain proteins that link the plasma membrane with the cytoskeleton while inducing concave deformations of the membrane. Based on these results, we hypothesize that Shigella generation of plasma membrane protrusions utilizes the cellular filopodia formation machinery. In this application, we propose a set of exploratory investigations to test our hypothesis. Our specific aims are as follows: Aim 1. Analysis of IRTKS functions involved in Shigella protrusion formation. Aim 2. Test the role of Tyr phosphorylation of IRTKS in S. flexneri protrusion formation. Aim 3. Determine whether other interactors of I-BAR domain proteins are required for efficient generation of plasma membrane protrusions by S. flexneri. The investigations proposed in this application are highly likely to generate new insights into the mechanisms of Shigella spread through the intestinal epithelium, as well as into the fundamental processes involved in cellular membrane protrusion, particularly filopodia formation.

描述（由申请人提供）：志贺氏菌是细胞内肠道人类病原体，通过基于肌动蛋白的运动移动到细胞外周，从而产生质膜突起，渗透到邻近的未感染细胞中并被邻近的未感染细胞吸收。质膜突起的产生对于志贺氏菌的传播至关重要，但所涉及的机制尚不清楚。 我们已经证明，细胞透明福明和 IRTKS 都是有效形成质膜突起和志贺氏菌通过细胞单层有效扩散所必需的。透明福明和 IRTKS 同源物 IRSp53 都是细胞丝状伪足尖端复合物的组成部分，并且两者都是丝状伪足有效形成所必需的。 IRTKS 和 IRSp53 是 I-BAR 结构域蛋白，可将质膜与细胞骨架连接起来，同时诱导膜发生凹形变形。基于这些结果，我们假设志贺氏菌利用细胞丝状伪足形成机制产生质膜突起。在此应用中，我们提出了一系列探索性研究来检验我们的假设。我们的具体目标如下： 目的 1. 分析志贺氏菌突起形成中涉及的 IRTKS 功能。 目标 2. 测试 IRTKS 的酪氨酸磷酸化在福氏弧菌突起形成中的作用。 目标 3. 确定福氏链霉有效生成质膜突起是否需要 I-BAR 结构域蛋白的其他相互作用因子。 本申请中提出的研究很可能产生新的见解 志贺氏菌通过肠上皮传播的机制，以及参与细胞膜突出的基本过程，特别是丝状伪足的形成。