Plastocyanin is the long-range electron carrier between photosystem II and photosystem I in plants
Plastocyanin is the long-range electron carrier between photosystem II and photosystem I in plants
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DOI：
10.1073/pnas.2005832117
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发表时间：
2020-06-30
影响因子：
11.1
通讯作者：
Kirchhoff, Helmut
中科院分区：
文献类型：
--
作者：
Hoehner, Ricarda;Pribil, Mathias;Kirchhoff, Helmut
在光合作用的电子传递中，大的多蛋白复合物由小的可扩散电子载体连接，其流动性受到大分子拥挤的挑战。对于高等植物的类囊体膜，一个长期存在的问题是，两个移动的电子载体，质体醌或质体蓝素，介导电子从堆叠的基粒类囊体的光系统II（PSII）本地化到遥远的未堆叠的区域的类囊体港口PSI。在这里，我们确认质体蓝素是远程电子载体，采用不同的基粒直径的突变体。此外，我们的研究结果解释了为什么高等植物的基粒直径范围很窄，因为质体蓝素的扩散距离较大，会危及电子传递的效率。根据最近的研究结果，类囊体的内腔，形成质体蓝素的扩散空间，经历动态膨胀/收缩，这项研究表明，质体蓝素扩散是一个重要的调节元件的植物光合电子传递。
In photosynthetic electron transport, large multiprotein complexes are connected by small diffusible electron carriers, the mobility of which is challenged by macromolecular crowding. For thylakoid membranes of higher plants, a long-standing question has been which of the two mobile electron carriers, plastoquinone or plastocyanin, mediates electron transport from stacked grana thylakoids where photosystem II (PSII) is localized to distant unstacked regions of the thylakoids that harbor PSI. Here, we confirm that plastocyanin is the long-range electron carrier by employing mutants with different grana diameters. Furthermore, our results explain why higher plants have a narrow range of grana diameters since a larger diffusion distance for plastocyanin would jeopardize the efficiency of electron transport. In the light of recent findings that the lumen of thylakoids, which forms the diffusion space of plastocyanin, undergoes dynamic swelling/shrinkage, this study demonstrates that plastocyanin diffusion is a crucial regulatory element of plant photosynthetic electron transport.