铜(Cu)是植物生长发育所必需的营养元素，但Cu缺乏或过量均会对植物产生毒害效应。因而植物在长期的进化过程中形成了一套内稳态机制来调控细胞内铜离子浓度。高亲和铜转运蛋白在Cu离子稳态调节过程中发挥重要功能，然而这些蛋白的内吞、分泌及胞内转运机制尚不清楚。本项目拟以拟南芥高亲和铜转运蛋白COPT1为研究对象，应用细胞生物学、分子生物学、生物化学等综合分析手段，结合高内涵细胞成像系统和胶体金免疫电镜等新技术，开展如下研究：1）研究Cu刺激前后COPT1在质膜上的分布模式及含量变化；2）明确COPT1的内吞途径和胞内转运模式以及对Cu离子流和Cu积累的影响；3）揭示COPT1的非经典分泌机制及在细胞Cu离子稳态平衡中的作用。这不仅对深入探讨植物如何适应环境Cu水平变化具有重要理论意义，而且为通过分子设计创制用于Cu污染环境修复工程植物提供有应用价值的基础。

Copper (Cu) is an essential nutrition element for plant growth and development, however, deficient or excess copper is detrimental to plants. Therefore plants have evolved complex and elaborate homeostatic mechanisms to control intracellular copper concentration. High-affinity copper transporters have a vital role in regulating copper homeostasis, whereas the mechanisms of their endocytosis, secretion and intracellular transport are unknown. In this project,we will employ several new methods and techniques, encompassing biochemistry, molecular and celluar biology, imaging (High Content Imaging System) and colloidal gold immunoelectron microscopy.This project will focus on the following three aspects of research using Arabidopsis highe-affinity copper transporter 1 (COPT1) protein: 1) To observe distribution pattern and determine contents of COPT1 in plasma membrane before and after Cu induction; 2) To study endocytic pathway and intracellular transport mode of COPT1, and their effects on copper flux and copper accumulation; 3) To reveal mechanism of unconventional secretion of COPT1 and its role in copper homeostasis. These results will not only be significant to go deeply how plants adapt to variations of environmental Cu levels, but also provide potential applications for creating engineered plants by molecular design for phytoremediation of copper polluted environment.