Molecular Mechanism of Photoperiodic Time Measurement

光周期时间测量的分子机制

• 批准号: 7596474
• 负责人: TAKATO IMAIZUMI
• 金额: $ 20.75万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7596474
• 关键词: Arabidopsis; Behavior; Binding; Biochemical; Circadian Rhythms; Cues; Developed Countries; Developing Countries; Development; Eukaryota; Failure; Family; Flavins; Flowers; Future; Gene Expression; Genes; Genetic; Genetic Transcription; Genomics; Goals; Health; Human; Knowledge; Light; Luciferases; Mammals; Measurement; Measures; Molecular; Monitor; Organism; Pathway interactions; Photoreceptors; Plant Model; Plants; Play; Proteins; Regulation; Reporter; Reproduction; Research; Research Personnel; Role; Screening procedure; Seasonal Affective Disorder; Seasonal Variations; Seasons; Signal Transduction; System; Time; Transcriptional Regulation; Ubiquitination; Western Blotting; base; circadian pacemaker; day length; in vivo; insight; novel; programs; reproductive success; research study; response; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): The failure of seasonal adaptations can have a critical impact on an organism's survival and reproductive success. In people, one example of this is Seasonal Affective Disorder (SAD). Although the mechanisms of SAD remain elusive, its cause is seasonal variation in light conditions. In order to integrate information about seasonal change into their development, many organisms have evolved mechanisms to sense changes in day length. The long-term goal of our research program is to elucidate the molecular mechanisms of day- length measurement. Although the molecular mechanisms of photoperiodism have not yet been well described in many organisms, recent advances in the study of photoperiodic flowering in the model plant Arabidopsis have shed some light on them. In Arabidopsis, the core of photoperiodic time-measurement mechanisms is circadian regulated transcription of the floral activator CONSTANS (CO) gene, and light regulated CO protein stability and activity. In this proposal, we intend to further characterize these core molecular mechanisms by focusing on the functions of FKF1 E3 ubiquitin ligase through genetic, biochemical, and genomic approaches. The knowledge obtained in plant photoperiodism has often facilitated discoveries in other systems. Therefore, findings made in this proposal will be important not only for plant research, but also for broader understanding of photoperiodism in mammals and other systems. In addition, the findings may even provide some conceptional cues to understanding the mechanisms of SAD. Moreover, this type of transcriptional regulation is likely conserved in all eukaryotes, thus the findings will contribute to the understanding of a fundamental transcriptional regulation mechanism. In conclusion, elucidating the photoperiodic flowering mechanism is important not only for understanding a major plant reproduction mechanism, one that is directly applicable for an improvement of crop yield (an important contributor to human health, especially in developing countries) but also in understanding a sophisticated ubiquitination-dependent transcriptional mechanism that is universal among organisms.

描述（由申请人提供）：季节性适应的失败可能会对生物的生存和生殖成功产生关键影响。在人们中，一个例子是季节性情感障碍（SAD）。尽管SAD的机制仍然难以捉摸，但其原因是光条件下的季节性变化。为了将有关季节性变化的信息整合到其发展中，许多生物已经发展了机制，以感知日长度的变化。我们的研究计划的长期目标是阐明日期测量的分子机制。尽管在许多生物体中尚未很好地描述光周期的分子机制，但模型植物拟南芥中光周期开花的最新进展已经对它们阐明了一些启示。在拟南芥中，光周期时间测定机制的核心是花卉激活剂康斯坦（CO）基因的昼夜节律转录，以及光调节的CO蛋白稳定性和活性。在此提案中，我们打算通过遗传，生化和基因组方法专注于FKF1 E3泛素连接酶的功能来进一步表征这些核心分子机制。在植物光周期中获得的知识经常在其他系统中促进发现。因此，本提案中提出的发现不仅对植物研究至关重要，而且对于对哺乳动物和其他系统中光周期的更广泛理解也很重要。此外，这些发现甚至可能提供一些概念提示来理解悲伤的机制。此外，这种类型的转录调节可能在所有真核生物中都保存，因此发现将有助于理解基本的转录调控机制。总而言之，阐明光周期开花机制不仅对于理解主要的植物生殖机制很重要，该机制直接适用于提高作物产量（尤其是人类健康的重要原因，尤其是在发展中国家），而且对于理解一种复杂的泛素化依赖性转录机制，这是有机体中普遍存在的。