Molecular Basis for Pre-Receptor Modulation of Plant Hormones by Acyl Acid Amido Synthetases

智慧的优点植物需要对周围的环境和环境的变化做出反应。 作为这些反应的一部分，植物使用各种激素，这些激素与动物中发现的激素在化学上无关，以改变它们的生长和新陈代谢。 两种主要的植物激素是茉莉酸和生长素。 这些分子的存在与否由受体感知，如果受体与激素结合，就会触发植物的生物变化模式。 该项目的重点是GH3酶家族的蛋白质，这些蛋白质化学修饰激素以促进或阻止受体识别这些分子。 GH3蛋白质将不同的氨基酸连接到激素上，这可以导致产生活性分子，如茉莉酸酯，或非活性分子，如生长素。 通过它们的生物化学活性，GH3蛋白可以控制受体的开启或关闭，并作为植物激素反应的前受体调节剂。 虽然GH3蛋白广泛存在于植物界，但对其生物化学功能知之甚少。 该项目旨在通过使用X射线晶体学来了解GH3蛋白的分子结构，研究GH3蛋白如何催化它们对化学上不同的植物激素的反应，更广泛的影响探索控制植物激素作用的分子基础将为植物激素作用的生物化学网络提供新的见解，为植物生长、害虫防御和作物可持续性分配资源。 例如，茉莉酸酯在改变与环境变化、害虫/病原体防御相关的各种化合物的代谢以及用于生物燃料和工业原料的化合物的生产中是至关重要的。 该项目还侧重于培养下一代多学科科学家。 该项目中使用的研究方法和问题跨越了生物学，化学和物理学之间的界限，通过在实验室和教学中整合x射线晶体学，生物化学和植物生物学。 此外，为了培养研究生，更广泛的影响力努力的很大一部分集中在本科教育上。 PI通过本科生论文工作（Bio200，Bio500和Chem490）积极招募本科生，华盛顿U。HHMI-SURF，CD-BioRAP（NSF-REU计划）和大一前生物学和生物医学研究暑期学者计划，并通过辉瑞-Solutia暑期学生和教师作为研究科学家（STARS）计划指导高中生。 PI是Bio4522的课程大师：蛋白质生物化学实验室，并在本科教学实验室课程中开发研究型项目（Jez等人，2007生物化学分子和Arkus Jez，2008 Biochem.Mol.& Biol. Educ.）。 Bio4522是一个以研究为导向的实验室，旨在让学生通过不同的研究阶段来研究科学问题并作为一个团队工作。 2010 - 2011年春季班的成功，在产生一些初步的数据，拟南芥GH3蛋白质的这一建议突出了本科教育的价值，这种方法。& 在本提案的时间范围内，本课程的每学期将侧重于通过检查来自生命之树中不同生物体的这些酶来研究GH3蛋白功能在进化过程中的发展。

Intellectual MeritPlants need to respond to their surroundings and changes in their environment. As part of those responses, plants use various hormones, which are chemically unrelated to those found in animals, to alter their growth and change metabolism. Two major types of plant hormones are the jasmonates and auxins. The presence or absence of these molecules is sensed by receptors, which if bound to the hormone trigger a pattern of biological changes in the plant. This project focuses on proteins of GH3 enzyme family that chemically modify the hormones to either promote or prevent the receptor from recognizing these molecules. The GH3 proteins attach different amino acids to the hormone, which can lead to production of an active molecule, as occurs with jasmonates, or an inactive molecule, as with the auxins. Through their biochemical activity, the GH3 proteins can control if the receptor is on or off and act as pre-receptor modulators of hormone responses in plants. Although the GH3 proteins are widespread across the plant kingdom, little is known about their biochemical function. This project aims to understand the molecular structure of the GH3 proteins by using x-ray crystallography, to investigate how the GH3 proteins catalyze their reactions on chemically diverse plant hormones, and to provide insight on the physiological roles of each GH3 protein in plant hormone responses.Broader ImpactExploring the molecular foundations for control of plant hormone action will provide new insight on the biochemical networks involved in allocating resources for plant growth, pest defenses, and crop sustainability. For example, jasmonates are critical in altering metabolism of various compounds related to environmental changes, pest/pathogen defenses, and production of compounds useful for biofuels and industrial feedstocks. The project also focuses on training the next generation of multidisciplinary scientists. The research methods and questions used in this project cross the boundaries between biology, chemistry, and physics by integrating x-ray crystallography, biochemistry, and plant biology in both the lab and in teaching. In addition, to training graduate students a large portion of the broader impact efforts focus on undergraduate education. The PI actively recruits undergraduate students through undergraduate thesis work (Bio200, Bio500, and Chem490), the Washington U. HHMI-SURF, CD-BioRAP (an NSF-REU program), and the pre-freshman Summer Scholars in Biology and Biomedical Research program, and mentors high school students through the Pfizer-Solutia Summer Students and Teachers as Research Scientists (STARS) program. The PI is course-master for Bio4522: Protein Biochemistry Lab and has a record of developing research-oriented projects in undergraduate teaching lab courses (Jez et al., 2007 Biochem. Mol. Biol. Educ. and Arkus & Jez, 2008 Biochem. Mol. Biol. Educ.). Bio4522 is a research-oriented lab designed to have students progress through different stages of research to examine a scientific question and to work as a team. The success of the Spring 2010 & 2011 classes in generating some of the preliminary data on the Arabidopsis GH3 proteins for this proposal highlights the value of this approach for undergraduate education. During the timeframe of this proposal, each semester of the course will focus on investigating the development of GH3 protein function across evolution by examining these enzymes from different organisms in the Tree of Life.