Characterisation of the role of PAM71, PAM71L and AtCGL20 in the biogenesis and function of photosystem II and the NAD(P)H dehydrogenase

类囊体多蛋白复合物光系统II（PSII）和NAD（P）H脱氢酶（NDH）的组装通过许多不同的中间状态进行，并且需要辅助蛋白，即所谓的组装因子。我们先前已经鉴定和表征了PSII组装因子PAM68，并且在预备实验中发现序列相关的PAM68HL蛋白表现得像NDH组装因子。此外，我们发现，减少表达的TerC，光合作用和植物发育所必需的蛋白质，以及缺乏叶绿体蛋白PAM 71的线，显示PSII装配突变体的表型特征。我们建议表征蛋白TerC和PAM71及其与PSII亚基和不同组装状态的关联，以及相应功能丧失系的详细表征。为了更全面地了解PSII的组装过程以及PSII组装因子的顺序作用，我们将利用分裂泛素系统、共免疫沉淀和双分子荧光互补技术，系统地分析TerC、PAM 71和PAM 68与PSII亚基以及其他PSII组装因子的相互作用。此外，PAM68 HL在NDH组装中的作用将通过分析功能丧失系和通过免疫共沉淀和双分子荧光互补鉴定PAM68 HL的相互作用物来表征。

The assembly of the thylakoid multiprotein complexes photosystem II (PSII) and NAD(P)H dehydrogenase (NDH) proceeds through a number of distinct intermediate states and requires auxiliary proteins, the so-called assembly factors. We have previously identified and characterized the PSII assembly factor PAM68, and found in preparatory experiments that the sequence-related PAM68HL protein behaves like a NDH assembly factor. In addition, we found that lines with reduced expression of TerC, a protein essential for photosynthesis and plant development, as well as lines lacking the chloroplast protein PAM71, display phenotypes characteristic for PSII assembly mutants. We propose to characterize the proteins TerC and PAM71 and their association with PSII subunits and distinct assembly states, together with a detailed characterisation of the corresponding loss-of-function lines. To obtain a comprehensive picture of PSII assembly and the sequential action of PSII assembly factors, we will systematically analyse the interactions of TerC, PAM71 and PAM68 with PSII subunits, as well as with other PSII assembly factors, by the split-ubiquitin system, coim-munoprecipitation and bimolecular fluorescence complementation. Moreover, the role of PAM68HL in NDH assembly will be characterized by analysing loss-of-function lines and identifying interactors of PAM68HL by coimmunoprecipitation and bimolecular fluorescence complementation.