Auxiliary factors required for the accumulation and functioning of the thylakoid ATP synthase

叶绿体F1 Fo-ATP合酶（cpATPase）将ATP合成与光驱动的电化学质子梯度偶联，并且包括两个部分，膜CFo亚复合物（质子通道）和外周CF 1亚复合物（包含用于可逆ATP合成的催化位点）。为了完全组装一个功能性的cpATPase复合物，需要各种辅助因子-用于表达位于叶绿体的cpATPase亚基基因（atp基因）或组装过程本身。虽然在原核生物和酵母中已知F1 Fo-ATP合酶的几个组装因子，但对于植物，仅组装因子ALB 4尚未被鉴定。此外，还描述了几种参与atp基因表达的植物蛋白。在这个项目中，我们希望描述两个新的辅助蛋白所需的cpATPase生物合成的模式植物拟南芥。第一个，AtCGL 160，似乎是一个真正的组装因子，并与CFo亚复合物的亚基物理相互作用。有趣的是，AtCGL 160除了包含植物特异性结构域外，还包含一个较短的部分，该部分与原核Atp 1/UncI蛋白有关，该蛋白也与ATP合成酶组装有关。因此，我们希望阐明AtCGL 160促进cpATPase组装的机制，该机制在原核Atp 1/UncI蛋白和真核CGL 160蛋白之间是否保守，并揭示AtCGL 160植物特异性部分的功能。我们已经确定的cpATPase生物合成所需的第二种蛋白质是AtCGLD 11。与AtCGL 160相反，AtCGLD 11蛋白是可溶性的，并且显示出表明在atp基因表达中的功能的mRNA表达模式。因此，我们将研究AtCGLD 11的功能，特别是在atp基因表达中的功能，包括可以检测其与整个叶绿体基因和转录本中任何一个的相互作用的全局方法。

The chloroplast F1Fo-ATP synthase (cpATPase) couples ATP synthesis to the light-driven electrochemical proton gradient and comprise two parts, the membranous CFo subcomplex that is a proton channel and the peripheral CF1 subcomplex that contains the catalytic sites for reversible ATP synthesis. To fully assemble a functional cpATPase complex, various auxiliary factors are needed - either for the expression of the chloroplast-located genes for cpATPase subunits (the atp genes) or for the assembly process itself. While several assembly factors of the F1Fo-ATP synthase are known in prokaryotes and yeast, for plants only the assembly factor ALB4 has been identified yet. In addition, a couple of plant proteins involved in atp gene expression have been described. In this project, we want to characterize two novel auxiliary proteins required for cpATPase biogenesis in the model plant Arabidopsis thaliana. The first one, AtCGL160, appears to be a true assembly factor and interacts physically with subunits of the CFo subcomplex. Interestingly, AtCGL160 contains besides a plant-specific domain also a shorter part, which is related to the prokaryotic Atp1/UncI proteins that have been also brought into connection with ATP synthase assembly. Therefore, we want to clarify the mechanism by which AtCGL160 promotes cpATPase assembly, whether this mechanism is conserved between prokaryotic Atp1/UncI proteins and eukaryotic CGL160 proteins, and reveal the function of the plant-specific part of AtCGL160. The second protein that we have identified to be required for cpATPase biogenesis is AtCGLD11. In contrast to AtCGL160, the AtCGLD11 protein is soluble and displays an mRNA expression pattern that suggests a function in atp gene expression. Therefore, we will characterise the function(s) of AtCGLD11 particularly in atp gene expression, including global approaches that can detect its interactions with any of the entire set of chloroplast genes and transcripts.