Nitric Oxide and Autophagy Regulation in Arabidopsis

拟南芥中的一氧化氮和自噬调节

• 批准号: 0817976
• 负责人: Janet Braam
• 金额: $ 72.8万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0817976&HistoricalAwards=false
• 关键词: Nitric; Oxide; Autophagy; Regulation; Arabidopsis

Robust homeostastic mechanisms are key to cellular survival. Cells must maintain stable and optimal intracellular conditions for proficient enzymatic and metabolic processes. However, a highly dynamic and often stressful environment inevitably leads to cellular disturbances. Increases in cytosolic free calcium and reactive oxygen species are examples of intracellular changes that result from many environmental stresses. Cells have evolved mechanisms to use these changes as second messengers. Calcium and redox sensor proteins perceive these signs of stress and convey information that activates not only cellular and physiological adaptive responses but also counterbalancing mechanisms to regain cellular homeostasis. The Arabidopsis CML24 protein may be not only a calmodulin-related calcium sensor but also a redox sensor. CML24 undergoes calcium-dependent conformational changes and also has the potential to form a disulfide bond in response to oxidation. Plants with mutant CML24 have altered nitric oxide accumulation and autophagy regulation. Thus, nitric oxide and autophagy regulation may be functionally linked in plants and such links may be critical for cellular homeostasis. The roles of calcium and redox in CML24 conformation, stability, protein interaction, and physiological function will be determined through biochemical, biophysical, and molecular genetic approaches. CML24's role in nitric oxide accumulation will be investigated through determining, in part, whether CML24 functions in an NOA1-, nitrate reductase-, and/or mitochondria-dependent nitric oxide synthesis pathway. Autophagy will be monitored to reveal whether CML24, and its calcium-binding ability and disulfide bond formation, are critical for regulation. Nitric oxide accumulation and autophagy mutants, in addition to cml24 mutants, will be characterized to determine potential linkages among nitric oxide, redox, and autophagy regulation.Broader ImpactsThis research will address fundamental and important questions about cellular stress perception and response and may bring transformative insight into the roles of calcium, redox, nitric oxide, and autophagy in cellular homeostasis. Such processes are critical for plant survival and productivity. Knowledge derived from these studies should aid practices aimed at improving agricultural efficiency and preserving natural environments under stress. Through the involvement of undergraduates, graduate students, and postdocs, this research will enhance the infrastructure of research and training. Students supported by this grant will be encouraged to participate in conferences and teaching opportunities. Training of women and students of underrepresented groups will be a high priority. Outreach activities, such as lab tours, science fair judging, and NSF Advance activities, will continue. Research results will be disseminated widely through publication, conference presentations, and websites. Mutants and transgenic lines will be freely accessible to the community. This work also involves collaboration at Rice University, across the US, and internationally.

强大的稳态机制是细胞生存的关键。细胞必须维持稳定和最佳的细胞内条件，以实现熟练的酶促和代谢过程。然而，高度动态且经常充满压力的环境不可避免地会导致细胞紊乱。细胞质游离钙和活性氧的增加是许多环境应激导致的细胞内变化的例子。细胞已经进化出利用这些变化作为第二信使的机制。钙和氧化还原传感器蛋白感知这些压力信号并传达信息，这些信息不仅激活细胞和生理适应性反应，而且还激活平衡机制以恢复细胞稳态。拟南芥CML24蛋白可能不仅是钙调蛋白相关的钙传感器，而且是氧化还原传感器。 CML24 经历钙依赖性构象变化，并且还具有响应氧化而形成二硫键的潜力。具有 CML24 突变体的植物改变了一氧化氮积累和自噬调节。因此，一氧化氮和自噬调节可能在植物中存在功能性联系，并且这种联系对于细胞稳态可能至关重要。钙和氧化还原在 CML24 构象、稳定性、蛋白质相互作用和生理功能中的作用将通过生化、生物物理和分子遗传学方法确定。 CML24 在一氧化氮积累中的作用将通过部分确定 CML24 是否在 NOA1、硝酸还原酶和/或线粒体依赖性一氧化氮合成途径中发挥作用来研究。将监测自噬以揭示 CML24 及其钙结合能力和二硫键形成是否对调节至关重要。除了 cml24 突变体之外，还将对一氧化氮积累和自噬突变体进行表征，以确定一氧化氮、氧化还原和自噬调节之间的潜在联系。 更广泛的影响这项研究将解决有关细胞应激感知和反应的基本和重要问题，并可能为钙、氧化还原、一氧化氮和自噬在细胞稳态中的作用带来变革性的见解。这些过程对于植物的生存和生产力至关重要。从这些研究中获得的知识应该有助于旨在提高农业效率和在压力下保护自然环境的实践。通过本科生、研究生和博士后的参与，这项研究将增强研究和培训的基础设施。受这笔赠款支持的学生将被鼓励参加会议和教学机会。对代表性不足群体的妇女和学生的培训将是一个高度优先事项。实验室参观、科学博览会评审和 NSF Advance 活动等外展活动将继续进行。研究成果将通过出版物、会议报告和网站广泛传播。突变体和转基因品系将免费向社区开放。这项工作还涉及莱斯大学、美国各地和国际上的合作。