Control of Respiratory Electron Flow: A Molecular Genetic Basis for the Alternative Oxidase

这项研究利用替代氧化酶的遗传方法来阐明线粒体对整体能量和碳平衡的贡献的调节。最初，焦点集中在被确认为编码至少部分交替氧化酶的基因(S)上。有大量关于替代氧化酶的生理数据，而分子/遗传数据如此之少，以至于这种氧化酶的初级序列应该会产生目前无法预测的答案。该项目的第二部分利用来自三个模型系统的替代氧化酶基因，以了解细胞色素和替代途径之间呼吸电子流的调节。%植物，真菌、蓝藻和许多其他生物既有正常的呼吸细胞色素途径，也有另一种“替代”途径。在这些生物体中，这一途径与总能量和碳平衡的关系是显而易见的，然而，我们对其特性的生化和遗传学知识极其有限。这项研究将为替代途径的“替代氧化酶”提供结构基础。它还将阐明植物组织中发育和环境诱导的替代氧化酶能力的可能机制。还将开发细胞色素和其他呼吸途径之间的电子流调节模型，为未来有关呼吸电子流调节的假说以及通过基因操作和转化的遗传学基础提供一个框架，以检验这些假说。

This research utilizes a genetic approach for the alternative oxidase to elucidate the regulation of the mitochondrial contribution to overall energy and carbon balance. Initially, the focus centers on the gene(s) identified as encoding at least part of the alternative oxidase. There is a vast amount of physiological data concerning the alternative oxidase and so little molecular/genetic data that the primary sequence of this oxidase should yield answers that cannot be predicted at this time. The second portion of this project utilizes alternative oxidase genes from three model systems in order to understand the regulation of respiratory electron flow between the cytochrome and alternative pathways.%%% Plants, fungi, cyanobacteria and many other organisms possess both a normal cytochrome pathway of respiration and another, "alternative", pathway. The significance of this pathway in relation to total energy and carbon balance in these organisms is evident, yet, our biochemical and genetic knowledge concerning its identity is extremely limited. This research will provide a structural basis for the "alternative oxidase" of the alternative pathway. It will also elucidate a possible mechanism for the developmental and environmentally induced alternative oxidase capacity in plant tissues. A model for the regulation of electron flow between the cytochrome and alternative pathways of respiration will also be developed, providing a framework for future hypotheses concerning the regulation of respiratory electron flow as well as a genetic basis through gene manipulation and transformation, to test such hypotheses.***//