The Role of Acidic Residues and the Electrochemical Potential in Membrane Protein Assembly

小行星9728344 通俗摘要 细胞生物学中的一个基本过程是蛋白质插入细胞膜并在膜内实现其独特和独特拓扑结构的方式。 该项目是基于本实验室对细菌的研究，以及发现某些细菌膜蛋白内的负电荷残基在膜插入中起着积极作用。 这种插入显然只需要跨膜的电化学梯度的能量。 假设是电化学梯度通过膜电位的直接驱动力促进插入将被易位的膜蛋白的特定区域中的带负电荷的氨基酸。 这与其他系统中的其他插入机制形成对比，在其他系统中，特定蛋白质的插入需要一组复杂的额外蛋白质，这些蛋白质必须识别易位的蛋白质并与之相互作用。新的假设将通过检查插入各种细菌蛋白质和杂合蛋白质构建体进行测试，这些蛋白质和杂合蛋白质构建体在被认为在易位中起作用的特定残基处突变。 将改变膜的pH值和电位，以评估这些因素对转运的作用。 对插入细菌膜机制的研究可能对理解真核细胞线粒体中的类似过程至关重要，因为这些细胞器被认为是从共生细菌进化而来的。 ***

9728344 Dalbey Lay Abstract A fundamental process in cell biology is the way in which proteins are inserted into cellular membranes and achieve their distinctive and unique topology within the membrane. This project is based on studies of bacteria in this laboratory and the discovery that negatively charged residues within certain bacterial membrane proteins play an active role in membrane insertion. This insertion apparently requires only the energy of the electrochemical gradient across the membrane. The hypothesis is that the electrochemical gradient promotes insertion by the direct driving force of the membrane potential on the negatively charged amino acids in the specific regions of the membrane protein that will be translocated. This is in contrast to other mechanisms of insertion in other systems in which insertion of specific proteins requires a complex set of additional proteins that must recognize and interact with the translocated protein. The novel hypothesis will be tested by examining the insertion of a variety of bacterial proteins and hybrid protein constructs that are mutated at specific residues thought to play a role in translocation. The membrane pH and potential will be changed to assess the role of these factors on transport. This research on the mechanism of insertion into bacterial membranes will likely be fundamentally important in the understanding of similar processes in mitochondria of eukaryotic cells since these cell organelles are believed to be evolutionarily derived from symbiotic bacteria. ***