Functional analysis of plant nucleotide metabolism: Purine and pyrimidine Phosphoribosyltransferase and nucleotide kinase gene families

核苷酸在植物生命周期中的许多生化和发育过程中具有重要功能。作为核酸、植物激素、辅因子和用于碳水化合物代谢的富含能量的前体（例如UDP-葡萄糖）的组分，核苷酸参与细胞功能和植物生长的基本过程。在植物中，嘧啶类UTP、UDP、UMP和各种UDP糖在蔗糖代谢和细胞壁合成中起重要作用。而几乎所有的酶在从头合成的途径是由单基因编码，参与抢救和嘧啶和嘌呤核苷酸系统之间的能量转移的步骤是由拟南芥中的多基因家族编码。该项目侧重于两个家族的作用：（a）分析尿嘧啶和嘌呤磷酸核糖基转移酶基因家族及其对整个植物核苷酸供应的贡献。使用国家的最先进的分子和生物化学技术，我们将显示是否有从头核苷酸合成和打捞回收途径在不同的生长条件下的贡献之间的发展和空间差异。(b)促进嘌呤和嘧啶核苷酸间能量磷酸转移的核苷单磷酸和二磷酸激酶编码基因家族的分析。

Nucleotides have essential functions in a multitude of biochemical and developmental processes during the life cycle of a plant. As components of nucleic acids, phytohormones, cofactors, and energy rich precursors for carbohydrate metabolism (e.g. UDP-glucose) nucleotides are involved in essential processes in cellular function and plant growth. In plants, the pyrimidines UTP, UDP, UMP and the various UDP sugars play an essential role in sucrose metabolism and cell wall synthesis. Whereas nearly all enzymes in the pathway for de novo synthesis are encoded by single genes, steps involved in salvage and in energy transfer between the pyrimidine and purine nucleotide system are encoded by multigene families in Arabidopsis. This project focuses on the roles of two families: (a) Analysis of the uracil and purine phosphoribosyltransferase gene families and their contribution to overall plant nucleotide supply. Using state-of-the-art molecular and biochemical technologies we will show whether there are developmental and spatial differences between the contribution of de novo nucleotide synthesis and salvage recycling pathways under different growth conditions. (b) Analysis of the gene families coding for nucleoside mono- and diphosphate kinases which facilitate energy phosphotransfer between purine and pyrimidine nucleotides.