Prokaryotic gene regulation by light and oxygen

光和氧的原核基因调控

• 批准号: 7255614
• 负责人: CARL Eugene BAUER
• 金额: $ 48.33万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-12-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7255614
• 关键词: Aerobic; Affect; Anabolism; Bacteria; Bacteriochlorophylls; Binding; Biochemical; Biological Models; Blood Vessels; Blood capillaries; Carbon; Cell Respiration; Cell physiology; Cells; Chlorophyll; DNA Binding; Disease; Energy Metabolism; Enzymes; Fermentation; Funding; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Goals; Growth; Growth Factor; Heme; Homologous Gene; Hydrogen; Laboratories; Light; Mammalian Cell; Mammals; Metabolic; Metabolism; Molecular; Nature; Nitrogen Fixation; Numbers; Organism; Oxidation-Reduction; Oxygen; Oxygen measurement, partial pressure, arterial; Pathway interactions; Phosphorylation; Phosphotransferases; Photosynthesis; Physiological; Physiological Processes; Process; Production; Proteobacteria; Range; Regulation; Respiration; Rhodobacter; Rhodobacter capsulatus; Rhodobacter sphaeroides; Role; System; Tetrapyrroles; Ubiquinone; Variant; Yeasts; capillary; carbon fixation; cell type; cofactor; diadenosine pyrophosphate; heme biosynthesis; light intensity; response; sensor; transcription factor; tumor growth

DESCRIPTION (provided by applicant): Alteration in oxygen tension affects gene expression in all cell types. In bacterial systems, oxygen regulates a variety of genes involved in aerobic versus anaerobic energy metabolism. Metabolic processes such as carbon fixation, nitrogen fixation, respiration and photosynthesis are 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 metabolic enzymes. In mammalian cells, a growing number of genes are known to be oxygen regulated such as vascular growth factors that are key regulators for the synthesis of new capillary sprouts from preexisting vessels. Besides physiological roles, these growth factors are involved in disease processes such as the stimulation of capillary formation during tumor growth. This proposal is centered on elucidating molecular details of how bacteria Rhodobacter capsulatus and Rhodobacter sphaeroides are able to sense changes in oxygen tension, and in response, alter gene expression. These related species are 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 are affected by alterations in oxygen tension, as well as by variations in light intensity. Regulation of cell physiology by light is also known to occur in a number of organisms ranging from bacterial to mammals and is a second process that is studied by this proposal. Indeed, one of the key oxygen regulated transcription factors studied in this proposal is also regulated by light intensity. As a model system for studying both oxygen and light regulation of gene expression, we have focused on the process of tetrapyrrole biosynthesis. This pathway is highly regulated by oxygen and light intensity and is responsible for the production of such important metabolites as B12, heme and chlorophylls.

描述（由申请人提供）：氧张力的改变影响所有细胞类型中的基因表达。在细菌系统中，氧调节参与有氧与无氧能量代谢的各种基因。代谢过程如碳固定、氮固定、呼吸和光合作用响应于氧的存在或不存在而被调节。在酵母和藻类细胞中，已知氧气会影响氧化防御基因和代谢酶的转录。在哺乳动物细胞中，已知越来越多的基因是氧调节的，例如血管生长因子，其是从先前存在的血管合成新的毛细血管芽的关键调节因子。除了生理作用外，这些生长因子还参与疾病过程，例如在肿瘤生长期间刺激毛细血管形成。该提案的重点是阐明细菌Rhodobacter capsulatus和Rhodobacter sphaeroides如何能够感知氧张力变化的分子细节，并作为响应，改变基因表达。这些相关物种能够以各种能量产生模式生长，包括有氧呼吸、厌氧发酵和光合作用。参与这些过程的基因的表达受到氧张力变化以及光强度变化的影响。光对细胞生理学的调节也已知发生在从细菌到哺乳动物的许多生物体中，并且是本提案研究的第二个过程。事实上，在这个提议中研究的关键氧调节转录因子之一也受到光强度的调节。作为一个模型系统研究氧气和光调控基因表达，我们集中在四吡咯生物合成的过程。该途径受氧气和光照强度的高度调节，并负责产生重要的代谢物，如B12，血红素和叶绿素。