Assembly of E.Coli Outer Membrane Proteins

描述（由申请人提供）：蛋白质折叠和组装是所有活细胞正常功能必须正确发生的中心生物学过程。 许多毁灭性的人类疾病，包括神经退行性阿尔茨海默病和朊病毒疾病，都是蛋白质折叠和组装紊乱的结果。 相对大量的细胞活动致力于确保蛋白质的正确折叠和组装。 在错误折叠的情况下，蛋白质被驱动到聚集和降解途径。 降解错误折叠的蛋白质是至关重要的，因为它们可能形成有毒的聚集体，这可能干扰正常的细胞功能。 因此，使聚集最小化（分子伴侣和折叠酶）或去除聚集体（蛋白酶）的组装因子是响应于细胞的蛋白质折叠状态而调节的互补细胞活性。 由于膜蛋白复杂的折叠行为，研究其组装一直是一项具有挑战性的任务。 然而，最近的爆炸在许多膜蛋白的结构分辨率，包括那些包括在这项研究中，给了一个新的动力膜蛋白生物合成领域。 该研究旨在了解E.大肠杆菌，TolC，折叠成一个新的三维结构。 TolC蛋白具有多种医学和生理学上的重要功能，包括抗生素流出和毒素分泌。 这项研究将确定和表征基因内和基因外的因素，有助于TolC的组装成由α-螺旋和β-链组成的三聚体桶。 这些方面将通过利用遗传，分子和生物化学方法进行研究。 现有的数据表明，TolC遵循与迄今为止研究的所有其他OMP不同的组装途径，从而提供了发现管理OMP靶向和组装的新原理的机会。

DESCRIPTION (provided by applicant): Protein folding and assembly are central biological processes that must occur correctly for the proper functioning of all living cells. Many devastating human diseases, including neurodegenerative Alzheimer and prion diseases, are the consequence of disarrayed protein folding and assembly. A relatively large amount of cellular activity is dedicated to ensure the correct folding and assembly of proteins. In the event of misfolding, proteins are driven to aggregation and degradation pathways. Degradation of misfolded proteins is crucial because they may form toxic aggregates, which can interfere with normal cellular functions. Assembly factors that minimize aggregation (chaperones and foldases) or remove aggregates (proteases) are therefore complementary cellular activities that are regulated in response to the protein-folding status of the cell. Studying the assembly of membrane proteins has been a challenging task owing to their complex folding behavior. However, a recent explosion in the structural resolution of many membrane proteins, including those included in this study, has given a renewed impetus to the field of membrane protein biogenesis. The proposed research is directed at understanding the assembly of a unique OMP of E. coli, TolC, which folds into a novel three-dimensional structure. The TolC protein carries out several medically and physiologically important functions, including antibiotic efflux and toxin secretion. This research will identify and characterize intragenic and extragenic factors that contribute to TolC's assembly into trimeric barrels composed of alpha-helices and beta-strands. These aspects will be studied through exploiting genetic, molecular, and biochemical methods. The available data show that TolC follows an assembly pathway distinct from all other OMPs studied so far, thus providing an opportunity to uncover novel principles governing OMP targeting and assembly.