Molecular, regulatory. and functional properties of alternative oxidases of non-angiosperm plants

分子, 调节.

• 批准号: 402551-2011
• 负责人: McDonald, Allison
• 金额: $ 2.33万
• 依托单位: Wilfrid Laurier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=506699
• 关键词: Molecular; regulatory.; functional; properties; alternative

Biological electron transport chains (ETCs) power life on this planet. All plant cells contain mitochondria which use oxygen while converting carbon molecules, such as sugars, into energy. Plant mitochondria contain two respiratory pathways: the cytochrome c oxidase pathway, which is found in most organisms, including humans, and the alternative oxidase (AOX) pathway, which has a more limited distribution. Despite the fact that AOX transcripts, protein levels, and enzyme activity increase during a wide variety of environmental stresses, the physiological role of AOX is unknown. The long term goal of my research program is to understand the central role that respiratory electron transport plays in metabolic and physiological adaptations to stress. This proposal describes my plans to: (A) identify and examine AOX genes in non-angiosperm (non-flowering) plants and confirm that they are expressed as functional enzymes, (B) test the hypothesis that non-angiosperm plant AOXs are monomeric (composed of one subunit) and are regulated differently than angiosperm AOXs, and (C) test the hypothesis that AOX proteins encoded by different AOX genes are capable of forming heterodimers and that this will influence the catalytic properties of the enzyme.The answers to these questions will help to shed light on the evolutionary history of AOX and, how AOX enzyme activity is regulated, the structure of AOX, and to confirm that AOX is present in all plants. Our results will contribute to an overall understanding of how metabolic flexibility in the mitochondria of plants allows them to cope with environmental stress and can, thereby, contribute to the improvement of crop species. My research program allows for the training of highly qualified personnel in bioinformatics, molecular biology, biochemistry, physiology, and evolution and serves to illustrate how a comparative and integrative approach to biology can contribute to advancing knowledge.

生物电子传递链（ETCs）是这个星球上生命的动力。所有植物细胞都含有线粒体，线粒体在将碳分子（如糖）转化为能量的同时利用氧气。植物线粒体包含两种呼吸途径：细胞色素c氧化酶途径（cytochrome c oxidase pathway）和替代氧化酶途径（alternative oxidase， AOX），前者存在于包括人类在内的大多数生物体中，后者分布较为有限。尽管AOX转录本、蛋白质水平和酶活性在各种环境胁迫下都会增加，但AOX的生理作用尚不清楚。我的研究计划的长期目标是了解呼吸电子传递在代谢和生理适应压力中所起的核心作用。本提案描述了我的计划：(A)在非被子植物（非开花）植物中鉴定和检测AOX基因并确认其作为功能酶表达；(B)验证非被子植物AOXs是单体（由一个亚基组成）并且与被子植物AOXs的调节方式不同的假设；(C)验证不同AOX基因编码的AOX蛋白能够形成异源二聚体并影响酶的催化性能的假设。这些问题的答案将有助于揭示AOX的进化史，以及如何调节AOX酶的活性，以及AOX的结构，并证实AOX存在于所有植物中。我们的研究结果将有助于全面了解植物线粒体的代谢灵活性如何使它们能够应对环境胁迫，从而有助于改善作物物种。我的研究项目旨在培养生物信息学、分子生物学、生物化学、生理学和进化方面的高素质人才，并说明生物学的比较和综合方法如何有助于提高知识水平。