叶绿体NDH复合物的生物发生需要大量核基因编码的生物发生因子在基因转录、转录后加工、亚基翻译、翻译后修饰以及分步组装等各个环节进行调控。我们采用反向遗传学对拟南芥FNA1基因进行RNAi干扰后获得了NDH活性特异性缺失的突变体fna1。进一步分析发现fna1中NDH亚复合物A无法累积，说明FNA1参与了NDH亚复合物A的生物发生。本项目拟以FNA1蛋白为出发点，从亚基翻译以及复合物组装等不同水平研究FNA1在NDH亚复合物A生物发生过程中的作用；采用酵母筛选、免疫亲和层析结合质谱鉴定等手段确定与FNA1相互作用的蛋白质和复合物；通过研究FNA1及相关复合物组分与可能靶蛋白之间的相互作用及作用方式来阐明FNA1及相关复合物在NDH亚复合物A生物发生特定过程中的具体功能。这些结果对于我们深入了解叶绿体NDH复合物的生物发生具有重要意义。

Biogenesis of the chloroplast NDH complex requires a large number of nucleus-encoded auxiliary and regulatory factors involved in different steps including transcription, RNA processing, RNA editing, splicing, translation and assembly. We used RNA interference (RNAi) to decrease the mRNA level of the FNA1 gene and found that NDH activity was specifically impaired in RNAi lines (fna1). Further biochemical analyses showed that NDH subcomplex A was absent in fna1 thylakoids，suggesting that FNA1 is involved in biogenesis of the NDH subcomplex A. The overall aim of this proposal is to characterize the molecular function of FNA1 and its associated protein complex in NDH subcomplex A biogenesis. The research objectives and strategies used in this work are: 1) Determination of the roles of FNA1 during the biogenesis of NDH subcomplex A. 2) Identification of the proteins and complexes associated with FNA1 using a yeast-two hybrid screen system and affinity chromatography in combination with mass spectrometry. 3) Determination of the protein-protein interaction between FNA1, components of the FNA1-associated complex and their putative targets. On the basis of the results obtained from this work, we will finally propose the molecular function of FNA1 and its related complex, which will provide new insights into the mechanisms of NDH biogenesis.