Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520, Turku, Finland.
Photochem Photobiol Sci. 2020 May 20;19(5):604-619. doi: 10.1039/d0pp00025f.
The photosystems (PS), catalyzing the photosynthetic reactions of higher plants, are unevenly distributed in the thylakoid membrane: PSII, together with its light harvesting complex (LHC)II, is enriched in the appressed grana stacks, while PSI-LHCI resides in the non-appressed stroma thylakoids, which wind around the grana stacks. The two photosystems interact in a third membrane domain, the grana margins, which connect the grana and stroma thylakoids and allow the loosely bound LHCII to serve as an additional antenna for PSI. The light harvesting is balanced by reversible phosphorylation of LHCII proteins. Nevertheless, light energy also damages PSII and the repair process is regulated by reversible phosphorylation of PSII core proteins. Here, we discuss the detailed composition and organization of PSII-LHCII and PSI-LHCI (super)complexes in the thylakoid membrane of angiosperm chloroplasts and address the role of thylakoid protein phosphorylation in dynamics of the entire protein complex network of the photosynthetic membrane. Finally, we scrutinize the phosphorylation-dependent dynamics of the protein complexes in context of thylakoid ultrastructure and present a model on the reorganization of the entire thylakoid network in response to changes in thylakoid protein phosphorylation.
光合作用系统（photosystems，PS）催化高等植物的光合作用反应，在类囊体膜中不均匀分布：PSII 与其光捕获复合物（light harvesting complex，LHC）II 一起富集在贴附的基质类囊体垛叠中，而 PSI-LHCI 位于非贴附的基质类囊体中，它们缠绕在基质类囊体垛叠周围。两个光系统在第三膜域——基质类囊体边缘相互作用，该边缘连接基质类囊体和垛叠类囊体，并允许松散结合的 LHCII 作为 PSI 的附加天线。光能的吸收通过 LHCII 蛋白的可逆磷酸化来平衡。然而，光能也会损伤 PSII，而修复过程受 PSII 核心蛋白的可逆磷酸化调节。在这里，我们讨论了被子植物叶绿体类囊体膜中 PSII-LHCII 和 PSI-LHCI（超）复合物的详细组成和组织，并探讨了类囊体蛋白磷酸化在光合作用膜中整个蛋白复合物网络动态中的作用。最后，我们在类囊体超微结构的背景下仔细研究了蛋白复合物的磷酸化依赖性动态，并提出了一个模型，说明整个类囊体网络在响应类囊体蛋白磷酸化变化时的重组。
