蓝藻cNAF调控NDH-1复合体组装的分子机制研究

Cyanobacterial NADPH dehydrogenase (NDH-1) plays a key role in multiple bioenergetic reactions, including cyclic electron transport around photosystem I, CO2 uptake and respiration. However, the molecular mechanism of NDH-1 complex assembly remains elusive. Recently, we identified an assembly factor for the NDH-1 hydrophilic subcomplex (cNAF1) in the cyanobacterium Synechocystis sp. strain PCC 6803 and found that cNAF1 exclusively existed in a NDH-1 assembly intermediate with a molecular mass of about 300 kDa (NAI300). Thus, we will first reveal the interrelationship between cNAF1 and NAI300. Further, we will clarify the molecular mechanism how cNAF1 regulates the assembly of NDH-1 hydrophilic arm. Finally, to improve the molecular regulation mechanism for the NDH-1 complex assembly and construct a relatively improved NDH-1 assembly model, we will screen, isolate and identify these novel assembly factors using the strategies of molecular biology, physiology and biochemistry. The clarification of such assembly model will certainly increase our understanding the structure and function of cyanobacterial NDH-1 complex and provide an important theory reference for understanding the structure and function of chloroplast NDH-1 complex in higher plants.

蓝藻NADPH脱氢酶（NDH-1）复合体在环式电子传递，CO2吸收和细胞呼吸等多个能量反应中扮演着一个决定性的角色，但至今人们对这一复合体组装的分子调控机制尚不清楚。最近，我们鉴定到一个蓝藻NDH-1亲水亚复合体的组装因子——cNAF1，并且这一组装因子专一地存在于一个300-kDa的中间组装复合物NAI300中。因此，本项目将首先揭示cNAF1与NAI300间的相互关系，并进一步阐明这一组装因子调控NDH-1亲水亚复合体组装的分子机制。然后，通过分子生物学、生理和生化等手段，筛选、分离和鉴定出新的NDH-1复合体组装因子，并揭示它们调控NDH-1复合体组装的分子机制；最终构建一个相对完善的NDH-1复合体组装模型。这一组装模型的构建必将增进人们对蓝藻NDH-1复合体结构与功能的理解，也将为理解高等植物叶绿体NDH-1复合体的结构与功能提供重要的理论参考。

蓝藻NDH-1复合体在环式电子传递，CO2吸收和细胞呼吸等多个能量反应中扮演着一个决定性的角色，但至今人们对这一复合体组装的分子调控机制尚了解不够。通过本项目的实施，我们鉴别出了4个NDH-1复合体组装因子，它们分别从NDH-1铁硫簇亚基（Ssr2781）、亲水臂（Ssl3829和Ssl3451）和超分子复合体（CpcG2）等方面调控蓝藻NDH-1复合体的组装过程，由此勾勒出了一幅蓝藻NDH-1复合体组装的模型图。相关的研究成果总结成9篇标注SCI学术论文发表在国际专业期刊上，其中，一区SCI论文3篇；二区SCI论文4篇；同时组建了一支研究蓝藻光合NDH-1的年轻队伍。这一组装模型的构建必将增进人们对蓝藻NDH-1复合体结构与功能的理解，也将为理解高等植物叶绿体NDH-1复合体的结构与功能提供重要的理论参考。