RTE, a plant growth gene with a conserved role in metals

描述(申请人提供)：广泛的，长期的目标是了解生物控制过渡金属离子的机制，以及这些金属，特别是铜，在细胞信号和调控途径中的作用。铜的动态平衡对人类健康具有重要意义，然而细胞内铜的转运途径尚不清楚，铜感应和铜转运的成分也相对较少。这项提议的重点是RTE，一个以前没有描述的新序列的基因，它被假设为编码铜的传感器、转运体或伴侣。RTE基因高度保守，在动物中以单拷贝形式存在，在植物中以双拷贝形式存在。这项建议的目的是确定RTE在金属动态平衡中的作用。这些研究将主要集中在模式植物拟南芥的RTE1基因上。拟南芥的遗传分析已经将RTE1与乙烯信号转导中的两个铜结合蛋白联系在一起。一种是需要铜的乙烯受体ETR1，其功能依赖于RTE1。另一个是RAN1，它是人类Menkes/Wilson的P型ATPase铜转运蛋白的同源物，同样是乙烯受体功能所必需的。研究拟南芥中这些与RTE1连接的遗传和细胞基础将利用强大的遗传工具来理解RTE的细胞作用。关于RTE和Menkes/Wilson的同系物CUA-1的平行实验将在动物遗传模型秀丽线虫中进行，允许将动物系统的结果与植物的结果进行比较和整合。将分别采用酿酒酵母和哺乳动物细胞培养进行乙烯结合试验和铜结合试验。拟议的实验将使用分子遗传学、细胞生物学和生化方法的组合。对RTE功能的阐明将直接影响对金属动态平衡过程的理解，从而造福人类健康。

DESCRIPTION (provided by applicant): The broad, long-term objective is to understand the mechanisms by which organisms control transition metal ions and the roles of these metals, particularly copper, in cell signaling and regulatory pathways. Copper homeostasis is of major importance to human health, yet the pathways for intracellular copper trafficking are unclear, and relatively few components in copper sensing and trafficking have been identified. This proposal focuses on RTE, a previously undescribed gene of novel sequence, which is hypothesized to encode a sensor, transporter or chaperone for copper. The RTE gene is highly conserved, and is present in a single copy in animals and in two copies in plants. The aim of this proposal is to define the role of RTE in metal homeostasis. The studies will center primarily on the RTE1 gene of the model plant Arabidopsis thaliana. Genetic analyses in Arabidopsis have linked RTE1 to two copper-binding proteins in ethylene signal transduction. One is the copper-requiring ethylene receptor ETR1, whose function is dependent on RTE1. The other is RAN1, a homolog of the human Menkes/Wilson's P-type ATPase copper transporter, which is likewise required for ethylene receptor function. Investigating the genetic and cellular basis for these connections to RTE1 in Arabidopsis will utilize powerful genetic tools for understanding the cellular roles of RTE. Parallel experiments with respect to RTE and the Menkes/Wilson's homolog CUA-1 will be performed in the animal genetic model Caenorhabditis elegans, allowing comparison and integration of results from an animal system with those in plants. Saccharomyces cerevisiae and mammalian cell culture will be employed for ethylene binding assays and copper binding assays, respectively. The proposed experiments will use a combination of molecular genetics, cell biology and biochemical methods. The elucidation of RTE function should have a direct impact on understanding the processes of metal homeostasis for the benefit of human health.