Molecular Mechanism of Photoperiodic Time Measurement

光周期时间测量的分子机制

• 批准号: 7547634
• 负责人: TAKATO IMAIZUMI
• 金额: $ 10.63万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 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/7547634
• 关键词: Arabidopsis; Behavior; Binding; Biochemical Genetics; Circadian Rhythms; Condition; Cues; Developed Countries; Developing Countries; Development; Eukaryota; Eukaryotic Cell; Failure; Family; Flavins; Flowers; Future; Gene Expression; Genes; Genetic Transcription; Genomics; Goals; Health; Human; Invasive; Knowledge; Light; Luciferases; Mammals; Measurement; Measures; Molecular; Monitor; Organism; Pathway interactions; Personal Satisfaction; Photoreceptors; Plant Model; Plants; Play; Proteins; Regulation; Reporter; Reproduction; Research; Role; Screening procedure; Seasonal Affective Disorder; Seasonal Variations; Seasons; Signal Transduction; System; Time; Transcriptional Regulation; Ubiquitination; Western Blotting; base; circadian pacemaker; day; 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对生物体的生存和繁殖成功产生重大影响。在人类中，季节性情感障碍（SAD）就是一个例子。尽管 SAD 的机制仍然难以捉摸，但其原因是光照条件的季节性变化。为了将季节变化的信息整合到它们的发育中，许多生物体已经进化出感知白天长度变化的机制。我们研究计划的长期目标是阐明日长测量的分子机制。尽管许多生物体中光周期现象的分子机制尚未得到很好的描述，但模式植物拟南芥光周期开花研究的最新进展已经为我们提供了一些线索。在拟南芥中，光周期时间测量机制的核心是花激活剂 CONSTANS (CO) 基因的昼夜节律调节转录，以及光调节的 CO 蛋白稳定性和活性。在本提案中，我们打算通过遗传、生化和基因组方法关注 FKF1 E3 泛素连接酶的功能，进一步表征这些核心分子机制。在植物光周期现象中获得的知识往往有助于其他系统的发现。因此，该提案中的发现不仅对于植物研究很重要，而且对于更广泛地了解哺乳动物和其他系统的光周期现象也很重要。此外，这些发现甚至可能为理解 SAD 的机制提供一些概念线索。此外，这种类型的转录调控可能在所有真核生物中都是保守的，因此这些发现将有助于理解基本的转录调控机制。总之，阐明光周期开花机制不仅对于理解一种主要的植物繁殖机制很重要，这种机制直接适用于提高作物产量（对人类健康的重要贡献，特别是在发展中国家），而且对于理解复杂的植物繁殖机制也很重要。泛素化依赖性转录机制在生物体中普遍存在。