CyanoP is Involved in the Early Steps of Photosystem II Assembly in the Cyanobacterium Synechocystis sp PCC 6803
CyanoP is Involved in the Early Steps of Photosystem II Assembly in the Cyanobacterium Synechocystis sp PCC 6803
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DOI：
10.1093/pcp/pcw115
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发表时间：
2016-09-01
影响因子：
4.9
通讯作者：
Komenda, Josef
中科院分区：
文献类型：
--
作者：
Knoppova, Jana;Yu, Jianfeng;Komenda, Josef
虽然PSII复合物是高度保守的蓝藻和叶绿体，PsbU和PsbV亚基稳定蓝藻中的氧释放Mn 4CaO 5簇是不存在的叶绿体中，并已被取代的PsbP和PsbQ亚基。然而，有一个遥远的蓝藻同系物PsbP，称为CyanoP，未知的功能。在这里，我们表明，CyanoP在PSII生物合成的早期阶段在集胞藻PCC 6803中发挥作用。CyanoP存在于PSII反应中心组装复合物（RCII）中，缺乏CP 47和CP 43模块，并与较小的D2模块结合。与FLAG标记的CyanoP共纯化的少量较大的PSII核心复合物表明CyanoP可以在其大部分组装途径上伴随PSII。在生物发生中的作用是由未组装的D1前体的积累和受损的形成RCII在缺乏CyanoP的突变体的支持。有趣的是，来自缺乏CP 47的菌株的CyanoP-FLAG的下拉制备物也含有PsbO，表明该蛋白质与PSII在组装中比先前假设的更早的阶段接合。
Although the PSII complex is highly conserved in cyanobacteria and chloroplasts, the PsbU and PsbV subunits stabilizing the oxygen-evolving Mn4CaO5 cluster in cyanobacteria are absent in chloroplasts and have been replaced by the PsbP and PsbQ subunits. There is, however, a distant cyanobacterial homolog of PsbP, termed CyanoP, of unknown function. Here we show that CyanoP plays a role in the early stages of PSII biogenesis in Synechocystis sp. PCC 6803. CyanoP is present in the PSII reaction center assembly complex (RCII) lacking both the CP47 and CP43 modules and binds to the smaller D2 module. A small amount of larger PSII core complexes co-purifying with FLAG-tagged CyanoP indicates that CyanoP can accompany PSII on most of its assembly pathway. A role in biogenesis is supported by the accumulation of unassembled D1 precursor and impaired formation of RCII in a mutant lacking CyanoP. Interestingly, the pull-down preparations of CyanoP-FLAG from a strain lacking CP47 also contained PsbO, indicating engagement of this protein with PSII at a much earlier stage in assembly than previously assumed.