ECF sigma factors in adaptation and virulence of Porphyromonas gingivalis

ECF sigma 因素影响牙龈卟啉单胞菌的适应和毒力

• 批准号: 8513305
• 负责人: Hansel M. Fletcher
• 金额: $ 34.13万
• 依托单位: LOMA LINDA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-18 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8513305
• 关键词: Affect; Agar; Anaerobic Bacteria; Architecture; Bacteria; Biochemical; Bioinformatics; Blood; Complex; DNA-Directed RNA Polymerase; Data; Development; Disease; Drug Design; Environment; Gene Expression; Genes; Genome; Goals; Health; Hemagglutination; Homeostasis; Human; Hydrogen Peroxide; Infection; Inflammatory; Invaded; Membrane; Molecular Genetics; Mutagenesis; Operon; Organism; PAWR protein; Pathogenesis; Pathogenicity; Pathway interactions; Periodontal Diseases; Periodontal Pocket; Pigments; Play; Porphyromonas gingivalis; Post-Transcriptional Regulation; Prevention; Property; Proteins; Recruitment Activity; Regulation; Regulon; Relative (related person); Research; Reverse Transcriptase Polymerase Chain Reaction; Role; Sigma Factor; Signal Transduction; Stress; System; Therapeutic; Transcription Initiation; Virulence; Virulence Factors; biological adaptation to stress; design; environmental change; gene function; gingipain; mutant; novel therapeutics; paralogous gene; pathogen; promoter; response; sensor; success; transcriptomics

DESCRIPTION (provided by applicant): Porphyromonas gingivalis is an important etiologic agent of periodontal disease. The harsh inflammatory conditions of the periodontal pocket, in addition to the environmental changes encountered during infection and colonization, suggest that this organism has properties that will facilitate its ability to respond and adapt to stress. Stress response in the pathogen is a major determinant of its virulence. In general, the response and adaptation mechanisms are known to be mostly regulated at the level of transcription initiation by extracytoplasmic function (ECF) sigma factor, the largest group of alternative sigma factors. To date, little is known about the relationship between the regulation of adaptive mechanisms, virulence, and ECF sigma factors in P. gingivalis. Because the hostile environment within the host will likely affect the membrane architecture of the invading bacteria, it is our hypothesis that in P. gingivalis ECF ¿ factors coordinately regulate mechanisms vital for protection against environmental stress and are significant in the pathogenicity of the organism. In the genome of Porphyromonas gingivalis W83, six putative ECF ¿ factors were identified. In preliminary studies, we have inactivated five ECF ¿ factor genes (PG0162, PG0214, PG0985, PG1660, and PG1827) by allelic exchange mutagenesis. Taken together, our findings suggest that in P. gingivalis ECF sigma factors can modulate important virulence factors. ECF ¿ factors encoded by the PG0162 and PG1660 genes might also be involved in the post-transcriptional regulation of the gingipains. Bioinformatics analysis suggests that PG0162 and PG1660 are paralogs that have unique properties. It is likely that they may be involved in unique and complex regulatory mechanisms. In this project, we wish to gain a comprehensive understanding of P. gingivalis ECF ¿ factors and their role in an adaptive response to the environmental conditions typical of the periodontal pocket. The Specific Aims are: (1) To confirm and characterize the properties of specific ECF sigma factors in P. gingivalis. (2) To identify the environmental stress signals and sensor protein(s) involved in the modulation of PG1660. (3) To identify the genes in the PG1660 regulon(s) and characterize the regulatory sequences involved in the expression of those genes. Collectively, the data generated will facilitate a comprehensive assessment of the role of ECF ¿ factors in regulating gene expression, identifying pathways of adaptation to environmental stress typical of the periodontal pocket and evaluating their impact on pathogenicity of P. gingivalis. Because many of the proteins in this study are unique, drugs designed to inhibit these targets could be an attractive therapeutic strategy to aid in the prevention of P. gingivalis-associated diseases.

描述（由应用提供）：卟啉单胞菌是牙周疾病的重要病因。除了在感染和定殖过程中遇到的环境变化外，牙周口袋的炎症条件还表明，该生物具有支持其反应和适应压力的能力。病原体中的压力反应是其病毒的主要决定剂。通常，已知响应和适应机制主要是在最大的替代sigma因子的最大群体群体质胞质功能（ECF）Sigma因子（ECF）Sigma因子（ECF）Sigma因子上进行调节的。迄今为止，对牙龈疟原虫的适应性机制，病毒和ECF Sigma因子的调节之间的关系知之甚少。由于宿主内的敌对环境可能会影响入侵细菌的膜结构，因此我们的假设是，在牙龈疟原虫中，ECF»因素协同调节机制对机制至关重要。 保护环境压力，对生物体的致病性很重要。在卟啉念珠菌W83的基因组中，发现了六个假定的ECF„因素。在初步研究中，我们通过等位基因交换诱变使我们灭活了五个ECF？因子基因（PG0162，PG0214，PG0985，PG1660和PG1827）。综上所述，我们的发现表明，在牙龈疟原虫中，ECF Sigma因子可以调节重要的病毒因子。 PG0162和PG1660基因编码的ECF»可能也参与了gingipains的转录后调节。生物信息学分析表明，PG0162和PG1660是具有独特特性的旁系同源物。他们可能参与了独特而复杂的调节机制。在这个项目中，我们希望对牙龈疟原虫的ECF„因素及其在对牙周口袋典型的环境条件的适应性反应中的作用中有全面的了解。具体目的是：（1）确认和表征牙龈疟原虫中特定ECF Sigma因子的性质。 （2）确定 PG1660调节涉及的环境应力信号和传感器蛋白。 （3）识别PG1660调节子中的基因，并表征与这些基因表达相关的调节序列。总体而言，生成的数据将促进对ECF»因素在控制基因表达中的作用的全面评估，从而确定适应牙周口袋典型的环境压力的途径，并评估其对牙龈疟原虫致病性的影响。由于本研究中的许多蛋白质都是独特的，因此旨在抑制这些靶标的药物可能是有助于预防牙龈疟原虫相关疾病的有吸引力的理论策略。