Regulation of Streptococcus mutans AtlA on the cell surface

描述（由申请人提供）：牙齿表面成熟生物膜的形成是口腔细菌存活和发病的重要组成部分。尽管在过去的几年中，口腔生物膜的复杂性已经被迅速揭示，但仍然缺乏对细菌如何以明确的方式建立成熟的致病性生物膜的理解，导致难以鉴定和设计用于抗生物膜疗法的新靶标。为此， 对变形链球菌主要自溶素AtlA的研究表明，它是生物膜成熟所需的，这是一种新的但关键的途径，可以更全面地了解这种生物体的生物膜发育。已证实的CIMA途径调节细胞表面重塑的能力是本提案中概述的研究的主要驱动力，为复杂的生物膜过程提供了新的范例，特别是与细胞表面结构和重塑过程相关的生物膜过程。在这一范围内，我们将把努力集中在三个相互关联的领域。在具体的目标1，我们将阐明如何在功能上和结构上与细胞表面通过分析的重复结构域的cDNAA蛋白。在特定目标2中，我们假设atlA操纵子内编码的基因产物主要调节atlA的表面定位和活性。在这个目标中，我们还试图确定额外的ESTA相关的组件，提高我们的理解的架构和功能的ESTA在细胞表面。在具体目标3中，我们将在小鼠龋齿模型中进行初步实验，以开始分析SAMA在S.变形菌龋齿发育。总的来说，本申请操纵了一个尚未表征的作用，在S。变形杆菌生物膜形成的影响，并且从这些提出的研究中获得的数据具有促进开发治疗龋齿的创新治疗策略的高潜力，例如通过干扰致龋生物膜的适当发展所必需的自溶途径。该项目也是我们阐明生物膜成熟及其潜在机制的分子基础的长期目标的一部分。

DESCRIPTION (provided by applicant): Development of a mature biofilm on the tooth surface is an important component of bacterial survival and pathogenesis in the oral cavity. Although over the past years, the complexity of the oral biofilm has been rapidly revealed, understanding how bacteria build up mature pathogenic biofilms in a well- defined way, is still lacking, leading to difficulty in identifying and designing new targets for anti-biofilm therapies. Toward this end, the study of the major Streptococcus mutans autolysin AtlA, shown to be required for biofilm maturation, is a new, but critical pathway for a more complete understanding for biofilm development of this organism. The demonstrated ability of the AtlA pathway to modulate cell surface remodeling is a major driving force for the studies outlined in this proposal, providing a new paradigm for the complex biofilm process particularly as related to the cell surface structure and remodeling process. Under this scope, we will focus our efforts in three interrelated areas. In Specific Aim1, we will elucidate how AtlA is functionally and structurally associated with the cell surface through analysis of repeat domains in the AtlA protein. In the Specific Aim 2, we hypothesize that surface localization and activity of AtlA are modulated primarily by the gene products encoded within the atlA operon. In this Aim, we also attempt to identify additional AtlA-associated components, enhancing our understanding of the architecture and function of AtlA on the cell surface. And in the Specific Aim 3, we will perform a pilot experiment in a mouse caries model to begin to analyze the in vivo impact of AtlA in S. mutans caries development. Overall, this application manipulates an as yet uncharacterized role of AtlA in S. mutans biofilm formation, and data derived from these proposed studies have a high potential to facilitate the development of innovative therapeutic strategies to treat dental caries, e.g. by interfering with the autolytic pathways necessary for the proper development of cariogenic biofilms. This project is also part of our long-term objective elucidating the molecular basis for biofilm maturation and its underlying mechanisms.