Molecular Mechanisms of Protein Association with Plastoglobule Lipid Droplets

本计画将探讨蛋白质与植物细胞光合区室中存在的质体小分子（lipid drops）结合的机制。越来越多的证据表明，质体对于植物有效耐受一系列环境胁迫是非常重要的。然而，目前还不清楚它们在细胞中发挥什么作用，以促进植物的胁迫耐受性。本研究将通过揭示质体小球蛋白质组的建立和动态调节的原理，阐明质体小球功能与逆境耐受性之间的关系。这项研究的结果可能为农业和园艺作物的发展提供基础，这些作物更有营养，更能适应环境挑战。该项目将为不同背景和职业阶段的研究人员提供科学培训。将根据该项目的概念和成果为小学生编写教材和课堂演示，该项目将为来自高度多样化的社会经济和族裔群体的数千名儿童提供服务。这些课程将教育学生植物作为食物来源的价值，植物在自然界中面临的挑战，以及植物科学在克服这些挑战中的作用。数十种结构蛋白和酶蛋白在叶绿体的质体小球脂滴表面周围缔合。这些质体小球相关蛋白质中的大多数已知特异性地与质体小球相关，尽管这种显著特异性的分子机制尚不清楚。该项目将采用综合的生物化学和显微技术来揭示蛋白质特定关联的机械原理。将通过检测截短和定点诱变蛋白的荧光定位来鉴定质体小球结合所需的序列区域。蛋白质和相关序列区域的脂质结合能力将使用脂质覆盖和囊泡结合实验进行研究。为了确定翻译后修饰对质体小球结合的影响，将对分离的叶绿体亚室进行自上而下和自下而上的蛋白质组学研究。该研究将在机械水平上发展对蛋白质-膜相互作用的理解，并对生命的所有领域产生影响，特别是其他弯曲或单层膜，如细胞质脂滴，胶束或脂蛋白颗粒。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

This project will explore the mechanisms of protein association with plastoglobules, lipid droplets that exist in the photosynthetic compartment of plant cells. Accumulated evidence indicates that plastoglobules are highly important for effective plant tolerance to a range of environmental stresses. However, it remains unclear what role they play in the cell to facilitate stress tolerance within plants. This research will unravel the relationship between plastoglobule function and stress tolerance by uncovering principles governing the establishment and dynamic regulation of the plastoglobule protein set. Results from this research may provide a foundation for development of agricultural and horticultural crops that are more nutritious and more resilient to environmental challenges. This project will provide scientific training to researchers of diverse backgrounds and career stages. Lesson materials and in-class demonstrations for elementary school students will be developed based on concepts and results of the project that will serve thousands of children from highly diverse socioeconomic and ethnic groups. These lessons will educate students about the value of plants as a source of food, the challenges plants face in nature, and the role of plant science in overcoming these challenges.Dozens of structural and enzymatic proteins associate peripherally at the surface of plastoglobule lipid droplets of chloroplasts. Most of these plastoglobule-associated proteins are known to specifically associate to the plastoglobule, although the molecular mechanisms which underlie this remarkable specificity are unknown. This project will employ integrated biochemical and microscopic techniques to uncover mechanistic principles governing the specific association of proteins. Sequence regions necessary for plastoglobule association will be identified by testing fluorescent localization of truncated and site-directed mutagenized proteins. Lipid-binding capabilities of proteins and relevant sequence regions will be investigated using lipid overlay and vesicle-binding experiments. To determine the impact of post-translational modifications on plastoglobule association, coupled top-down and bottom-up proteomics will be conducted on isolated chloroplast sub-compartments. The research will develop understanding of protein-membrane interactions at a mechanistic level, with implications for all domains of life, particularly other curved or monolayer membranes such as cytoplasmic lipid droplets, micelles, or lipoprotein particles.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.