GENETIC ANALYSIS OF PROTEIN EXPORT

蛋白质输出的遗传分析

• 批准号: 7391173
• 负责人: Thomas J. Silhavy
• 金额: $ 61.71万
• 依托单位: PRINCETON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7391173
• 关键词: ATP phosphohydrolase; Affect; Alleles; Bacteria; Bacterial Infections; Bacterial Typing; Bypass; Cell physiology; Complex; Culture Media; Diffuse; Endopeptidases; Escherichia coli; Galactosidase; Goals; Helix (Snails); Infection; Isomerase; LacZ Genes; Life; Lipid Bilayers; Membrane; Membrane Proteins; Molecular Chaperones; Mutation; Peptide Hydrolases; Peptide Signal Sequences; Periplasmic Proteins; Phase; Phenotype; Protein Export Pathway; Protein Secretion; Proteins; RNA Sequences; Role; Secretory Component; Signal Recognition Particle; Signal Transduction Pathway; Stress; Suppressor Genes; Suppressor Mutations; Testing; Thinking; Toxic effect; Urinary tract infection; Work; crosslink; disulfide bond; ear helix; genetic analysis; in vivo; membrane biogenesis; mutant; novel; periplasm; prevent; protein folding

Protein secretion is an essential cellular process. Signal sequences, RNA-containing targeting factors (Signal Recognition Particle, SRP), and a translocation machinery that contains a heterotrimeric complex o membrane proteins have been discovered in all three domains of life. In Escherichia coli, signal sequences are found on proteins destined for the inner or outer membranes, the periplasmic space located between these lipid bilayers, and on proteins that are secreted into the growth media. The prokaryotic SEP (pSRP) containsa protein, Ffh and 4.5S RNA, and the heterotrimeric membrane protein complex is comprised of SecY (PrlA), SecE (PrlG), and SecG (PrlH). Secretory components that are unique to bacteria include the secretion specific chaperone, SecB, and a translocation ATPase, SecA (PrlD). The prl alleles of the various sec genes are suppressor mutations that restore the secretion o: preproteins with defective signal sequences. We have shown that PrlA and PrlG act by abolishing a signal sequence proofreading function, and we will test our hypothesis that signal sequences interact directly with transmembrane helix 7 of SecY. In vivo crosslinking of SecY and SecE by disulfide bonding, and depletion of Ffh cause similar phenotypes. We will test whether this indicates a more fundamental role for pSRP. We will also explore the possibility that a novel mutation,prlFl, affects a targeting activity of SecYEG for inner membrane proteins. We have discovered partially overlapping signal transduction pathways (Cpx and aE) that control the synthesis of periplasmic protein folding factors and a protease. We will continue our search for additiona factors and we will investigate how these molecules function in outer membrane biogenesis. In addition, we will determinethe mechanism by which the histidinekinase CpxA senses envelope stress, and we will test our prediction that Cpx is the master regulator of the "attached" phase during urinary tract infection. Results o: these studies may suggest new ways to treat or prevent certain types of bacterial infections.

蛋白质分泌是一个重要的细胞过程。信号序列、含RNA靶向因子 （信号识别颗粒，SRP），以及包含异源三聚体复合物的易位机器 膜蛋白已在生命的所有三个领域中被发现。在大肠杆菌中，信号序列 发现于前往内膜或外膜的蛋白质上，周质空间位于这些膜之间 脂质双层以及分泌到生长培养基中的蛋白质。原核 SEP (pSRP) 包含 蛋白、Ffh和4.5S RNA，异源三聚体膜蛋白复合物由SecY (PrlA)组成， SecE (PrlG) 和 SecG (PrlH)。细菌特有的分泌成分包括分泌特异性 分子伴侣 SecB 和易位 ATP 酶 SecA (PrlD)。 各种 sec 基因的 prl 等位基因是恢复分泌的抑制突变： 具有缺陷信号序列的前蛋白。我们已经证明 PrlA 和 PrlG 通过消除信号来起作​​用 序列校对功能，我们将测试我们的假设，即信号序列直接与 SecY 的跨膜螺旋 7。通过二硫键和耗尽实现 SecY 和 SecE 的体内交联 Ffh 引起相似的表型。我们将测试这是否表明 pSRP 具有更根本的作用。我们 还将探索一种新的突变，prlFl，影响 SecYEG 内层靶向活性的可能性。 膜蛋白。 我们发现了部分重叠的信号转导途径（Cpx 和 aE）控制着 周质蛋白折叠因子和蛋白酶的合成。我们将继续寻找更多 我们将研究这些分子如何在外膜生物发生中发挥作用。此外，我们 将确定组氨酸激酶 CpxA 感知包膜应激的机制，我们将测试我们的 预测 Cpx 是尿路感染期间“附着”阶段的主要调节因子。结果： 这些研究可能会提出治疗或预防某些类型细菌感染的新方法。