The Role of Prenylation in Meristem Function

异戊二烯化在分生组织功能中的作用

• 批准号: 0344261
• 负责人: Mark Running
• 金额: --
• 依托单位: Donald Danforth Plant Science Center
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0344261&HistoricalAwards=false
• 关键词: Role; Prenylation; Meristem; Function

The activities of shoot meristems are the primary determinants for establishing the overall aerial architecture of the plant: its stature, the numbers and positions of branches, leaves, and flowers, the time to maturation, and the course of flower and fruit development. Meristems act by integrating external environmental signals with genetic cues to determine numbers and positions of primordia initiation events. These activities are simultaneously coordinated with signaling events that regulate cell divisions within the meristem, which assures continued maintenance of meristem cell populations while the meristem allocates cells to primordia and stem production. Dr. Running designed a sensitized Arabidopsis screen that allows for rapid identification of mutants that affect meristem function. Among the mutants he isolated was pluripetala, which shows a progressive loss of control of shoot meristem cell proliferation, along with shorter stature and extra floral organs. He cloned PLURIPETALA and found that it encodes the alpha subunit shared between the prenylation enzymes farnesyltransferase and geranylgeranyltransferase-I. Prenylation is a lipid posttranslational modification that facilitates membrane localization and association of target proteins, particularly proteins involved in signal transduction. Unlike equivalent prenylation mutants in animal and yeast systems, pluripetala plants are viable and fertile. Therefore, pluripetala mutant plants provide a unique opportunity for testing the functional role of prenylation of proteins in vivo, including the effects of prenylation on protein subcellular localization and cell-cell trafficking. In addition, identification of prenylation targets using bioinformatics and experimental assays will provide insight into components of signaling pathways involved in meristem function and flower development. His specific aims are to: (1) examine the role of prenylation in plant growth and development; (2) examine the specific roles of each component of the prenylation complex and their relation to each other; and (3) determine the functional role of prenylation on two potential target proteins in plants. The proposed activity will improve understanding of the role of prenylation in plants, which is involved in a number of processes, including meristem function, flower development, and hormone responses. These processes are of interest to a wide variety of plant scientists and have potential applications for agriculture. His multidisciplinary approach to the study of plant development combines genetics, molecular biology, and cellular biology techniques and will provide excellent training opportunities for postdoctoral fellows and students. In addition, he is developing a summer workshop for local high school teachers for continuing science education. This program will involve instruction, demonstration, and hands-on experience in laboratory research, which will be carried out in part in the Running lab. Educational resources will also be developed for classroom instruction. Lastly, he is developing a web-based resource for disseminating information on lipid posttranslational modifications, including prenylation, in plants. This database includes information on the identification of putative targets using bioinformatics tools along with those that have been experimentally confirmed. Experiments in this proposal will allow for updates and refinement to this database, which we expect will be very useful to members of the plant scientific community because of the vast number of processes in which lipid post translational modification plays a role.

茎分生组织的活动是建立植物整体气生结构的主要决定因素：其高度，枝，叶和花的数量和位置，成熟时间以及花和果实发育的过程。 分生组织通过整合外部环境信号和遗传线索来决定原基起始事件的数量和位置。 这些活动同时与调节分生组织内细胞分裂的信号事件协调，这确保了分生组织细胞群体的持续维持，同时分生组织将细胞分配给原基和干细胞产生。 Running博士设计了一个敏感的拟南芥筛选器，可以快速鉴定影响分生组织功能的突变体。 在他分离出的突变体中，有一种是多瓣的，这种突变体表现出对茎分生组织细胞增殖的逐渐失控，沿着出现矮小和额外的花器官。 他克隆了PLURIPEALA，发现它编码异戊烯化酶法尼基转移酶和香叶基香叶基转移酶-I之间共有的α亚基。 异戊烯化是一种脂质翻译后修饰，其促进靶蛋白，特别是参与信号转导的蛋白的膜定位和缔合。与动物和酵母系统中的等价异戊烯化突变体不同，多瓣花属植物是可行的和可育的。 因此，pluripetala突变体植物提供了一个独特的机会，在体内测试的功能作用的异戊二烯化的蛋白质，包括异戊二烯化蛋白质的亚细胞定位和细胞-细胞运输的影响。 此外，使用生物信息学和实验测定的异戊二烯化目标的识别将提供深入了解分生组织功能和花发育所涉及的信号通路的组成部分。 他的具体目标是：（1）研究异戊烯化在植物生长和发育中的作用;（2）研究异戊烯化复合物中每种组分的具体作用及其相互关系;（3）确定异戊烯化对植物中两种潜在靶蛋白的功能作用。拟议的活动将提高对异戊二烯化在植物中的作用的理解，异戊二烯化涉及许多过程，包括分生组织功能、花发育和激素反应。 这些过程是各种各样的植物科学家感兴趣的，并有潜在的农业应用。 他对植物发育研究的多学科方法结合了遗传学，分子生物学和细胞生物学技术，并将为博士后研究员和学生提供极好的培训机会。此外，他正在为当地高中教师举办一个暑期讲习班，以继续进行科学教育。 该计划将涉及实验室研究的指导，演示和实践经验，这将部分在运行实验室进行。 还将为课堂教学开发教育资源。最后，他正在开发一个基于网络的资源，用于传播植物中脂质翻译后修饰（包括异戊二烯化）的信息。 该数据库包括关于使用生物信息学工具鉴定推定靶点的信息，沿着那些已经实验证实的靶点。该提案中的实验将允许更新和完善该数据库，我们预计这将是非常有用的植物科学界的成员，因为大量的过程中，脂质翻译后修饰发挥作用。