双定位蛋白DRR1参与核质基因组稳定性双重调控机制研究

质体是植物特有的半自主性细胞器，质体基因组和细胞核基因组之间的功能协调对于细胞正常的功能维持至关重要，但相关的协调机理并不清楚。我们前期鉴定到一个功能未知的质体和细胞核双定位蛋白DRR1，初步研究发现DRR1参与核质基因组稳定性的双重调控。在细胞核，DRR1中与DNA预复制复合物相互作用，影响DNA复制起始；在质体中，DRR1与基因组稳定性调控因子Whirly蛋白相互作用，影响质体基因组重排效率。更为有趣的是，在不同组织中，DRR1有着不同的亚细胞分布。本项目拟在此基础上，深入探究DRR1在核质基因组双重控制中的的调控机制。首先遗传分析DRR1在植物生长发育及光合作用中的生理功能；继而阐释DRR1在核质基因组稳定性维持中的异同；最后探讨DRR1蛋白输入细胞核和质体的调控机制。本项目将解析DRR1在质体和细胞核基因组稳定性维持中的作用机理，从而揭示一种由核质双定位蛋白介导的核质协调新策略。

Plastids are plant-specific semi-autonomous organelles. The functional coordination between the plastid genome and the nuclear genome is essential for the maintenance of normal cell functions. However, The mechanism of coordination is not clear. We previously identified a plastid-nucleus dual-localized protein DRR1 with unknown function. Preliminary studies have shown that DRR1 is involved in the dual regulation of genome stability in plastid and nucleus. In the nucleus, DRR1 interacts with DNA pre-replication complexes, affecting the initiation of DNA replication. In plastids, DRR1 interacts with Whirly protein, a genome stability regulator, which affects the efficiency of plastid DNA rearrangement. More interestingly, DRR1 has different subcellular distribution in different tissues. On this basis, this project intends to further explore the regulatory mechanism of DRR1 in the dual control of nuclear and plastid genome. Firstly, the physiological function of DRR1 in plant growth and development, as well as photosynthesis will be checked by genetic analysis. Then, the similarities and differences of DRR1 in maintaining the stability of nuclear genome will be elucidated. Finally, the regulatory mechanism of DRR1 protein input into nucleus and chloroplast will be explored. This project will clarify the mechanism of DRR1 in maintaining the stability of plastid and nuclear genome, and reveal a novel strategy of nuclear-plastid coordination mediated by nuclear-plastid dual-localized proteins.