Antioxidant metabolism in Chlamydomonas

衣藻的抗氧化代谢

基本信息

批准号：
6868299
负责人：
KRISHNA K NIYOGI
金额：
$ 19.74万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-01-01 至 2009-02-28
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Several antioxidant small molecules that are synthesized by plants are essential vitamins in the human diet. These nutrients, including vitamin A precursors (carotenoids), vitamin E (tocopherols), and vitamin C (ascorbate), have critical functions in quenching and scavenging reactive oxygen species that are inevitable byproducts of metabolism in all aerobic organisms, from bacteria to plants and animals. Despite the importance of antioxidant vitamins for human health, many fundamental questions remain unanswered about their function and the regulation of their biosynthesis. This proposal addresses several of these questions using molecular genetic, genomic, and physiological approaches in a tractable, unicellular green alga, Chlamydomonas reinhardti. Chlamydomonas represents a powerful eukaryotic model organism for studying antioxidant metabolism in plants, much like the budding yeast Saccharomyces cerevisiae is used as a model for animals. The specific aims of this proposal are (1) to complete a molecular and genetic analysis of carotenoid biosynthesis in Chlamydomonas, (2) to generate a series of mutants affecting tocopherol composition in order to test the antioxidant function of different tocopherols in vivo, (3) to examine functional overlap between carotenoids and tocopherols as antioxidants in polyunsaturated lipid membranes, and (4) to perform genomic and genetic analyses of how carotenoid and tocopherol levels are regulated in cells by environmental factors, such as light intensity. This investigation will provide new insights into the roles of lipid-soluble antioxidants in preventing age-related diseases such as macular degeneration in humans and will provide a foundation for rational modification of carotenoid and tocopherol composition and content in plants to benefit human nutrition and health.

描述（申请人提供）：植物合成的几种抗氧化小分子是人类饮食中必需的维生素。这些营养物质，包括维生素 A 前体（类胡萝卜素）、维生素 E（生育酚）和维生素 C（抗坏血酸），在淬灭和清除活性氧方面具有关键功能，活性氧是所有需氧生物（从细菌到植物和植物）代谢过程中不可避免的副产品。动物。尽管抗氧化维生素对人类健康很重要，但有关其功能及其生物合成调节的许多基本问题仍未得到解答。该提案利用分子遗传学、基因组和生理学方法在易处理的单细胞绿藻莱茵衣藻中解决了其中几个问题。衣藻代表了一种强大的真核模型生物，用于研究植物中的抗氧化代谢，就像芽殖酵母酿酒酵母被用作动物模型一样。该提案的具体目标是（1）完成衣藻类胡萝卜素生物合成的分子和遗传分析，（2）产生一系列影响生育酚组成的突变体，以测试不同生育酚的体内抗氧化功能，（3 ）检查类胡萝卜素和生育酚作为多不饱和脂质膜中的抗氧化剂之间的功能重叠，以及（4）对类胡萝卜素和生育酚如何发挥作用进行基因组和遗传分析细胞中的水平受环境因素（例如光强度）的调节。这项研究将为脂溶性抗氧化剂在预防人类黄斑变性等年龄相关疾病中的作用提供新的见解，并为合理修饰植物中类胡萝卜素和生育酚的组成和含量以造福人类营养和健康提供基础。