Bacterial cell envelope in polar positioning of autotransporter proteins

描述（由申请人提供）：自身转运蛋白是革兰氏阴性菌中最丰富的分泌蛋白家族。其中许多已被鉴定为毒力蛋白。我们以前已经表明，自转运蛋白分泌在细菌的极点，这些蛋白质的目标是在细菌细胞质中的极点，之前跨细胞质膜分泌。我们的初步数据表明，细胞分裂蛋白FtsQ参与建立极性位置的信息，由autotransporters和FtsQ的周质域是足够的生成这个信息。我们提出探索性调查的作用，细胞包膜重塑的极性位置信息，在细胞质中的自转运蛋白的建立。我们的具体目标是：1.表征在建立志贺氏菌属的极性中有缺陷的FtsQ突变体。自体转运蛋白IcsA. 2.使用无偏方法鉴定和表征FtsQ途径下游自转运蛋白极性中的蛋白质。3.使用候选方法鉴定并表征在自转运蛋白极性途径中与FtsQ相互作用的蛋白质。我们在本申请中提出的探索性研究将深入了解原核生物中极性建立和细胞包膜动态发育和重塑的机制。

DESCRIPTION (provided by applicant): Autotransporters are the most abundant family of secreted proteins in gram-negative bacteria. Many of those that have been characterized are virulence proteins. We have previously shown that autotransporter proteins are secreted at the bacterial pole and that these proteins are targeted to the pole in the bacterial cytoplasm, prior t secretion across the cytoplasmic membrane. Our preliminary data indicate that the cell division protein FtsQ is involved in establishing polar positional information recognized by autotransporters and that the periplasmic domain of FtsQ is sufficient for the generation of this information. We propose exploratory investigations into the role of cell envelope remodeling in the establishment of polar positional information that is recognized in the cytoplasm by autotransporter proteins. Our specific aims are: 1. Characterize mutants of FtsQ defective in establishing polarity of the Shigella spp. autotransporter IcsA. 2. Identify using an unbiased approach, and characterize, proteins in the pathway downstream of FtsQ in autotransporter polarity. 3. Identify using a candidate approach, and characterize, proteins that interact with FtsQ in the autotransporter polarity pathway. The exploratory investigations we propose in this application will generate insights into the mechanisms involved in the establishment of polarity and into the dynamic development and remodeling of the cell envelope in prokaryotes.