Regulation of Streptococcus gordonii glucosyltransferase

名称：S。戈登氏葡萄糖基转移酶（GTF）合成葡聚糖，葡聚糖可以影响细菌在牙菌斑生物膜中的积累。正在进行的项目（DE 11090）的工作假设是，S.戈登氏菌涉及复杂的分子相互作用物，其可能对口腔中的细菌定殖和存活具有生态学意义。本研究的目的是探讨葡萄糖基转移酶表达调控的环境信号和分子机制。gordonii。在本补充申请中描述的所提出的研究的具体目的是使用DNA微阵列来鉴定和表征与GTF结构基因gtfG及其正调控决定子rgg的表达相关的协调调控的遗传网络。将亲本菌株的Gone表达谱与其中参与GTF活性的基因（例如rgg和gtfG）已被特异性灭活的菌株进行比较。拟议的实验还将检查这些细菌菌株在特定环境条件下的基因表达，这会影响GTF活性水平。微阵列方法将允许基本上全基因组，高灵敏度的搜索协调表达的基因。将使用定量实时聚合酶链反应（PCR）验证所得结果。这些研究中的微阵列的构建将通过使用现有的DNA克隆集来促进，这些DNA克隆集来自S. gordonii测序项目;这些分子工具在最初的母基金申请时还没有。对于这个补充申请，微阵列实验将集中在解决母基金的工作假设。拟议补充研究的结果将专门用于加速和补充正在进行的遗传和功能研究。这些研究旨在阐明GTF在S. gordonii的研究，阐明了合成葡聚糖对牙菌斑生物学的贡献。

DESCRIPTION: The S. gordonii glucosyltransferase (GTF) enzyme synthesizes glucans that can influence the accumulation of bacteria in the developing Dental plaque biofilm. The working hypothesis of the ongoing project (DE 11090) is that regulation of GTF activity in S. gordonii involves complex molecular interactor(s) that may have ecological implications for bacterial colonization and survival in the oral cavity. The goal of this ongoing project is to investigate the environmental signals and molecular mechanisms that regulate glucosyltransferase expression in the commensal species, S. gordonii. The Specific Aim of the proposed studies described in this Supplemental Application, is to use DNA microarrays to identify and characterize coordinately regulated genetic networks associated with expression of the GTF structural gene, gtfG and its positive regulatory determinant, rgg. Gone expression profiles of the parent strain will be compared to strains in which genes involved in GTF activity (e.g. rgg and gtfG) have been specifically inactivated. The proposed experiments will also examine gene expression in these bacterial strains under specific environmental conditions, which influence the level of GTF activity. Microarray methodology will allow an essentially genome-wide, highly sensitive search for coordinately expressed genes. The results obtained will be validated using quantitative real-time polymerase chain reaction (PCR). Construction of microarrays for these proposed studies will be facilitated by the use of existing DNA clone sets available from the parental strain Challis used in the S. gordonii sequencing project; these molecular tools were not available at the time of the original parent grant application. For this Supplemental Application, microarray experiments will be focused on addressing the working hypothesis of the parent grant. The results of the proposed supplemental studies will be used specifically to accelerate and supplement ongoing genetic and functional studies in the parent grant. These studies are designed to unravel the complex mechanisms involved in regulation of GTF expression in S. gordonii and elucidate the contributions of the synthesized glucans to the biology of Dental plaque.