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

类囊体多蛋白复合体光系统II(PSII)和NAD(P)H脱氢酶(NDH)的组装通过一些不同的中间状态进行，需要辅助蛋白质，即所谓的组装因子。我们以前已经鉴定并鉴定了PSII组装因子PAM68，并在前期实验中发现，与序列相关的PAM68HL蛋白的行为类似于NDH组装因子。此外，我们还发现，光合作用和植物发育所必需的蛋白质TERC表达降低的品系，以及缺乏叶绿体蛋白PAM71的品系，都表现出PSII组装突变体的表型特征。我们建议表征蛋白质TERC和PAM71及其与PSII亚基和不同组装状态的关联，以及相应功能丧失线的详细表征。为了全面了解PSII组装以及PSII组装因子的顺序作用，我们将通过分裂泛素体系、免疫共沉淀和双分子荧光互补等方法，系统地分析TERC、PAM71和PAM68与PSII亚基以及与其他PSII组装因子的相互作用。此外，PAM68HL在NDH组装中的作用将通过分析功能丧失线和通过免疫共沉淀和双分子荧光互补鉴定PAM68HL的相互作用来表征。

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.