Molecular analysis of the relatedness between adenosine, methylation and cytokinin metabolism

植物代谢的许多变化与基因表达的变化有关。此外，许多基因产物作用于不止一种底物。我对这些过程的融合很感兴趣。例如，小分子如何调节基因表达？当这些底物可能同时以不同的浓度存在时，细胞如何利用一种酶来产生一种以上的底物？我对植物中腺苷再循环的研究使我认识到腺苷激酶（ADK）对于维持细胞中数百种甲基化活动以及促进细胞分裂素（一类重要的植物生长调节剂）的相互转化至关重要。我们的集体结果提出了ADK和其他甲基再循环酶如何移动到细胞中甲基化位点的模型。拟议的研究将通过研究ADK参与甲基再循环和细胞分裂素代谢的特定蛋白质-蛋白质相互作用来测试该模型。此外，我们将研究参与这些过程的关键酶活性的诱导性过度表达和表达不足对发育和代谢的影响。最后，我们将整合的结果到一个数学模型的甲基回收。拟议的实验将提供新的见解甲基化是如何保持在不同的亚细胞区室，以及这是如何与细胞分裂素在植物中的相互转换。

Many changes in plant metabolism are associated with changes in gene expression. Furthermore many gene products act on more than one substrate. I am fascinated by the integration of these processes. For example, how do small molecules act to regulate gene expression? How does a cell utilize an enzyme for more than one substrate when these substrates may be present at the same time, in differing concentrations? My research on adenosine recycling in plants has led to the realization that adenosine kinase (ADK) is essential for maintaining the hundreds of methylation activities in cells as well as contributing to the interconversion of cytokinins, an important class of plant growth regulators. Our collective results suggest a model of how ADK and other methyl recycling enzymes move to sites of methylation in the cell. The proposed research will test this model by investigating specific protein-protein interactions for ADK's involvement in methyl recycling and cytokinin metabolism. In addition we will investigate the developmental and metabolic effects of inducible over- and under-expression of key enzyme activities participating in these processes. Finally we will integrate the results into a mathematical model of methyl recycling. The proposed experiments will provide new insight into how methylation is maintained in different subcellular compartments and how this is related to cytokinin interconversion in plants.