Gene Regulation in Glyoxysome Biogenesis

乙醛酸酶体是一种特殊的过氧化物酶体， 这对于脂质的动员至关重要。研究 原田博士， 正在研究编码异柠檬酸的基因的调节 裂合酶和苹果酸合酶，两种乙醛酸循环酶， 只与乙醛酸酶体相关。基因是受调控的 发育;它们在幼苗中表达，发育 种子、衰老器官和花粉中，但非衰老的 成熟植物的器官。此外，基因的调节 主要发生在转录水平。该提案的 长期目标是定义生理信号， 调节这些基因，从而控制乙醛酸酶体 生物起源一个附带的目标是确定 共同的信号调节这些基因在不同的时期， 植物生命周期提出了两种主要方法来解决 这些问题首先，原田博士将定位顺式作用元件 并鉴定与这些蛋白相互作用的DNA结合蛋白 获得对法规的机械理解的要素 的基因。第二，他将识别出突变体， 基因的表达，以开始定义的组成部分， 调节基因的途径。他预计，这些 补充研究最终将提供深入了解 控制乙醛酸体生物发生的生理线索。

Glyoxysomes are specialized peroxisomes that contain enzymes critically required for the mobilization of lipids. To study processes involved in the biogenesis of the organelle, Dr. Harada is investigating the regulation of genes encoding isocitrate lyase and malate synthase, two glyoxylate cycle enzymes that are associated exclusively with glyoxysomes. The genes are regulated developmentally; they are expressed in seedlings, developing seeds, senescent organs, and in pollen but not in non-senescent organs of the mature plant. Moreover, regulation of the genes occurs primarily at the transcriptional level. The proposal's long term goal is to define the physiological signals that regulate these genes, and, therefore, control glyoxysome biogenesis. An accompanying objective is to determine whether a common signal regulates these genes at different periods of the plant life cycle. Two primary approaches are proposed to address these issues. First, Dr. Harada will localize cis-acting elements and identify the DNA binding proteins that interact with these elements to obtain a mechanistic understanding of the regulation of the genes. Second, he will identify mutants altered in the expression of the genes to begin to define components of the pathway regulating the genes. He anticipates that these complementary studies ultimately will provide insight into the physiological cues that control glyoxysome biogenesis.