Prokaryotic Gene Regulation By Light and Oxygen

描述(由申请人提供)：已知氧分压的改变 影响所有细胞类型的基因表达。在细菌系统中，氧气影响 有氧与无氧能量相关的多种基因的表达 如硝酸还原酶和细胞色素氧化酶等世代。.的存在 氧活性物质，也影响参与防御的基因的表达 防止氧化损伤。各种额外的新陈代谢过程，如 固碳、固氮和产氧光合作用也是 对有无氧作出反应而调节的。在酵母和藻类中 在细胞中，氧已知会影响氧化防御基因的转录以及参与糖酵解的酶。在哺乳动物细胞中，越来越多的 已知的基因是氧气调节的，比如那些编码生长因子的基因。 如促红细胞生成素和血管内皮生长因子是关键 用于从已有的导管合成新的毛细管芽的调节剂。 除了生理作用，这些生长因子也与疾病有关。 在肿瘤生长过程中刺激毛细血管形成等过程。 这项提议的中心是阐明氧气如何通过分子细节 影响细菌中的基因表达。作为一个模型系统，我们研究氧气 调控基因在胶囊红杆菌中的表达与其密切相关 线粒体谱系。这个物种能够在各种不同的 能量产生方式包括好氧呼吸、厌氧发酵 和光合作用。参与这些过程中每一个过程的基因表达 已知受到氧分压变化的影响，以及受 光线强度的变化。因此，这种有机体本身就是一种 研究基因氧光调控的重要模型系统 在许多生物系统中表达。

DESCRIPTION (provided by applicant): Alterations in oxygen tension are known to affect gene expression in all cell types. In bacterial systems, oxygen affects expression of a variety of genes involved in aerobic versus anaerobic energy generation such as nitrate reductase and cytochrome oxidase. The presence of oxygen reactive species, also affects expression of genes involved in defense against oxidative damage. A variety of additional metabolic processes such as carbon fixation, nitrogen fixation, and anoxygenic photosynthesis are also regulated in response to the presence or absence of oxygen. In yeast and algal cells, oxygen is known to affect transcription of oxidative defense genes as well as enzymes involved glycolysis. In mammalian cells, a growing number of genes are known to be oxygen regulated such as those coding for growth factors such as erythropoietin and vascular endothelithial growth factors that are key regulators for the synthesis of new capillary sprouts from preexisting vessels. Besides physiological roles, these growth factors are also involved in disease processes such as the stimulation of capillary formation during tumor growth. This proposal is centered on elucidating molecular details of how oxygen affects gene expression in bacteria. As a model system, we study oxygen regulated gene expression in Rhodobacter capsulatus which is closely related to the mitochondrial lineage. This species is capable of growth in a variety of energy generating modes including aerobic respiration, anaerobic fermentation and photosynthesis. The expression of genes involved in each of these processes is known to be affected by alterations in oxygen tension and well as by variations in light intensity. As such, this organism offers itself as an important model system to the study oxygen and light regulation of gene expression in a number of biological systems.