STATE TRANSITION7-Dependent Phosphorylation Is Modulated by Changing Environmental Conditions, and Its Absence Triggers Remodeling of Photosynthetic Protein Complexes
STATE TRANSITION7-Dependent Phosphorylation Is Modulated by Changing Environmental Conditions, and Its Absence Triggers Remodeling of Photosynthetic Protein Complexes
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DOI：
10.1104/pp.15.00072
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发表时间：
2015-06-01
期刊：
影响因子：
7.4
通讯作者：
Hippler, Michael
中科院分区：
文献类型：
--
作者：
Bergner, Sonja Verena;Scholz, Martin;Hippler, Michael
在植物和藻类中，丝氨酸/苏氨酸激酶STN 7/STT 7（分别在莱茵衣藻和拟南芥中的原丝蛋白激酶）是适应变化的光环境的重要调节剂。在这项工作中，我们评估了STT 7依赖的蛋白磷酸化在强光下在C。reinhardtii，已知完全诱导光捕获复合应激相关蛋白3（LHCSR 3）的表达和非光化学猝灭机制，与其中刺激循环电子流活性的缺氧有关。我们的定量蛋白质组学数据揭示了许多独特的STT 7蛋白底物和STT 7依赖的蛋白磷酸化变异，这些变异依赖于环境条件。这些结果表明，STT 7依赖的磷酸化是由环境调节，并指出一个复杂的叶绿体磷酸化网络响应在一个高度敏感和动态的方式对环境的线索和激酶功能的改变。在功能上，STT 7激酶的缺乏引发了蛋白质表达和光系统I（PSI）的光抑制的变化，并导致光合复合物的重塑。这种重构引发了LHCSR 3与PSI-光捕获复合物I（LHCI）-铁氧还蛋白-NADPH氧化还原酶超复合物的显著缔合。STT 7激酶的缺乏强烈削弱PSII-LHCII超复合物，而PSII核心复合物的磷酸化和积累显着增强。总之，我们的研究提供了强有力的证据表明，蛋白质磷酸化的调节是至关重要的驱动成功驯化高光和缺氧的生长环境，并提供了新的见解驯化策略，这些环境条件。
In plants and algae, the serine/threonine kinase STN7/STT7, orthologous protein kinases in Chlamydomonas reinhardtii and Arabidopsis (Arabidopsis thaliana), respectively, is an important regulator in acclimation to changing light environments. In this work, we assessed STT7-dependent protein phosphorylation under high light in C. reinhardtii, known to fully induce the expression of LIGHT-HARVESTING COMPLEX STRESS-RELATED PROTEIN3 (LHCSR3) and a nonphotochemical quenching mechanism, in relationship to anoxia where the activity of cyclic electron flow is stimulated. Our quantitative proteomics data revealed numerous unique STT7 protein substrates and STT7-dependent protein phosphorylation variations that were reliant on the environmental condition. These results indicate that STT7-dependent phosphorylation is modulated by the environment and point to an intricate chloroplast phosphorylation network responding in a highly sensitive and dynamic manner to environmental cues and alterations in kinase function. Functionally, the absence of the STT7 kinase triggered changes in protein expression and photoinhibition of photosystem I (PSI) and resulted in the remodeling of photosynthetic complexes. This remodeling initiated a pronounced association of LHCSR3 with PSI-LIGHT HARVESTING COMPLEX I (LHCI)-ferredoxin-NADPH oxidoreductase supercomplexes. Lack of STT7 kinase strongly diminished PSII-LHCII supercomplexes, while PSII core complex phosphorylation and accumulation were significantly enhanced. In conclusion, our study provides strong evidence that the regulation of protein phosphorylation is critical for driving successful acclimation to high light and anoxic growth environments and gives new insights into acclimation strategies to these environmental conditions.