Studies on the virulence regulation in Porphyromonas

 描述（由申请人提供）：牙龈卟啉单胞菌是一种黑色、革兰氏阴性厌氧菌，是牙周病的重要病原体，也与心血管疾病、类风湿性关节炎和其他全身性疾病有关。最近将牙龈卟啉单胞菌指定为“关键病原体”进一步强调了其适应牙周袋的苛刻炎症条件并破坏宿主-微生物稳态的能力，这部分地负责牙周病中观察到的病理学。因此，为了生存和协调可能导致疾病的微生物/宿主活动，表明牙龈卟啉单胞菌具有复杂的调控网络，可能涉及转录和转录后机制。虽然调节牙龈卟啉单胞菌致病潜力的关键因素是几种主要表面蛋白/结构的翻译后修饰，但我们对该回路的组分和机制的理解存在差距。本申请中要解决的具体假设是，通过乙酰化，新的vimA（毒力调节）基因产物参与牙龈卟啉单胞菌中几种主要表面蛋白的翻译后控制，包括牙龈菌蛋白酶成熟/活化。该假设基于在前一资助期中进行的观察，其中我们表征了bcp-recA-vimA-vimE-vimF-aroG基因座。该操纵子对于牙龈卟啉单胞菌蛋白酶的成熟/活化/锚定和牙龈卟啉单胞菌的其他毒力因子的调节是必需的。VimA在抗氧化应激中也很重要。我们的数据支持VimA在调节牙龈卟啉单胞菌毒力中的多功能作用，可能通过其参与乙酰化，这可能影响A-LPS合成，蛋白分选/转移/锚定和基因表达。在这个项目中，我们希望扩展这些发现，并更充分地阐明通过乙酰化进行毒力调节的VIMA依赖性机制。在包括口腔病原体在内的细菌中，乙酰化在毒力调节中的作用尚未得到很好的表征。我们研究计划的长期目标是阐明牙龈卟啉单胞菌毒力调控的全面分子机制，作为开发新型治疗干预措施的先决条件，以帮助控制和预防与这种关键病原体相关的疾病。参与乙酰化的VimA可能是一个基础， 革兰氏阴性厌氧菌中一种新的转录/翻译后控制机制的成员。本申请旨在全面评估VimA的多功能作用。具体目的：（1）研究乙酰化在蛋白质中的作用 牙龈卟啉单胞菌中的成熟。(2)评价Vima依赖性乙酰化对牙龈卟啉单胞菌中牙龈卟啉菌蛋白酶活化的影响。总的来说，本研究的结果将阐明VimA在牙龈卟啉单胞菌毒力调节中的机制作用。这将有助于阐明牙龈卟啉单胞菌中的乙酰化调控网络。它将生成一个模型系统， 重要的线索，这将有助于开发新的治疗干预措施，以帮助控制和预防牙周病

 DESCRIPTION (provided by applicant): Porphyromonas gingivalis, a black-pigmented, Gram-negative anaerobe, is an important etiological agent of periodontal disease and is also linked to cardiovascular disease, rheumatoid arthritis and other systemic diseases. The recent designation of P. gingivalis as a "keystone pathogen" further highlights its ability to adapt to th harsh inflammatory conditions of the periodontal pocket and disrupt host-microbial homeostasis, which is partly responsible for the pathology observed in periodontal disease. Thus, to survive and orchestrate the microbial/host activities that can lead to disease, suggest that P. gingivalis possesses a complex regulatory network probably involving transcriptional and post-transcriptional mechanisms. While a key element in modulating the pathogenic potential of P. gingivalis is the post- translational modification of several of the major surface proteins/structures, there is a gap in our understanding of the components and mechanism(s) of this circuitry. The specific hypothesis to be addressed in this application is that via acetylation the novel vimA (virulence modulating) gene product is involved in the post-translational control of several major surface proteins in P. gingivalis including gingipain maturation/activation. This hypothesis is based on the observations made in the previous funding period where we have characterized the bcp-recA-vimA-vimE-vimF-aroG locus. This operon is essential for the maturation/activation/anchorage of the gingipains and regulation of other virulence factors of P. gingivalis. VimA is also important in oxidative stress resistance. Our data support a multifunctional role for VimA in modulating virulence in P. gingivalis possibly through its involvement in acetylation, that may affect A-LPS synthesis, protein sorting/transfer/anchorage and gene expression. In this project, we wish to extend these findings and to more fully clarify the VimA-dependent mechanism(s) of virulence regulation via acetylation. In bacteria including oral pathogens, the role of acetylation in virulence regulation has not been well characterized. The long term objective of our research program is to elucidate a comprehensive molecular mechanism(s) for virulence regulation in P. gingivalis as a prerequisite to the development of novel therapeutic interventions to aid in the control and prevention of diseases associated with this keystone pathogen. It is likely that VimA, which is involved in acetylation, may be a founding member of a novel transcriptional/post-translational control mechanism in Gram-negative anaerobic bacteria. The current application is designed for a comprehensive assessment of the multifunctional role of VimA. The specific aims: (1) To evaluate the role of acetylation in protein maturation in P. gingivalis. (2) To evaluate the effects of VimA-dependent acetylation on gingipain activation in P. gingivalis. Collectively, the results from this study will clarify the mechanistic role of VimA in virulence regulation in P. gingivalis. It should shed light on the acetylation regulatory network in P. gingivalis. It will generate a model system(s) that will yield important clues that will facilitate the development of novel therapeutic interventions to aid in te control and prevention of periodontal disease