Analysis of prophyrin-mediated signaling pathways for the control of nuclear genes by the chloroplast

该项目集中在细胞内通信的一个方面：从叶绿体到细胞核的信号。高等植物的研究和我们对衣藻的研究已经为四吡啶及其生物合成中的酶在叶绿体到细胞核信号传导中的作用提供了证据。该项目的目标是介导这种交流的基因和分子的分子和功能表征。为此，我们将识别这种交流中有缺陷的突变体，并描述改变的基因及其产物。在互补方法中，对叶绿体信号作出反应的增强子序列将用于表征与其结合的蛋白质。在突变体中，它们的叶绿素前体水平和参与四吡啶生物合成的核基因表达都表现出失调，我们计划剖析叶绿体到细胞核信号传导改变的基础。

The project is focussed on one aspect of intracellular communication: the signaling from chloroplast to nucleus. Studies with higher plants and our work with Chlamydomonas have provided evidence for a role of tetrapyrroles and of enzymes involved in their biosynthesis in chloroplast-to-nucleus signaling. The goal of the project is the molecular and functional characterization of genes and molecules that mediate this communication. For this purpose, we will identify mutants defective in this communication and characterize the altered genes and their products. In a complementing approach, an enhancer sequence that responds to a chloroplast signal will be employed to characterize protein(s) that bind to it. And in mutants that exhibit a deregulation in both, their chlorophyll precursor levels and in the expression of nuclear genes involved in tetrapyrrole biosynthesis, we plan to dissect the basis for the altered signaling from chloroplast to nucleus.