Arabidopsis STN7 Kinase Provides a Link between Short- and Long-Term Photosynthetic Acclimation
Arabidopsis STN7 Kinase Provides a Link between Short- and Long-Term Photosynthetic Acclimation
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DOI：
10.1105/tpc.108.064964
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发表时间：
2009-08-01
期刊：
影响因子：
11.6
通讯作者：
Leister, Dario
中科院分区：
文献类型：
--
作者：
Pesaresi, Paolo;Hertle, Alexander;Leister, Dario
有花植物响应光质量的变化来控制其光系统的能量分配。这包括捕光复合物II（LHCII）蛋白的磷酸化和迁移（状态转换或短期响应）以及类囊体组成的长期改变（长期响应或LTR）。这两种反应都需要类囊体蛋白激酶STN7。在这里，我们表明，触发状态转换和LTR的信号通路在STN7处或其下游立即发散。这两种反应都需要STN7活性，其可以根据质体醌池氧化还原状态进行调节。然而，LTR信号传导不涉及LHCII磷酸化或任何其他状态转换步骤。状态转换似乎在显花植物中起着重要作用，并且在类囊体电子传递受损但保留功能性LTR的拟南芥突变体中，执行状态转换的能力对于光合作用变得至关重要。我们的数据表明，STN7依赖的磷酸化的一个未知的类囊体蛋白触发LTR信号转导事件，从而参与的TSP9蛋白的信号转导途径可以被排除。LTR信号事件，然后最终调节叶绿体中的光合作用相关基因的表达在转录水平上，而核编码的蛋白质的表达在多个水平上进行调节，如在LTR突变体中的转录和蛋白质谱所示。
Flowering plants control energy allocation to their photosystems in response to light quality changes. This includes the phosphorylation and migration of light-harvesting complex II (LHCII) proteins (state transitions or short-term response) as well as long-term alterations in thylakoid composition (long-term response or LTR). Both responses require the thylakoid protein kinase STN7. Here, we show that the signaling pathways triggering state transitions and LTR diverge at, or immediately downstream from, STN7. Both responses require STN7 activity that can be regulated according to the plastoquinone pool redox state. However, LTR signaling does not involve LHCII phosphorylation or any other state transition step. State transitions appear to play a prominent role in flowering plants, and the ability to perform state transitions becomes critical for photosynthesis in Arabidopsis thaliana mutants that are impaired in thylakoid electron transport but retain a functional LTR. Our data imply that STN7-dependent phosphorylation of an as yet unknown thylakoid protein triggers LTR signaling events, whereby an involvement of the TSP9 protein in the signaling pathway could be excluded. The LTR signaling events then ultimately regulate in chloroplasts the expression of photosynthesis-related genes on the transcript level, whereas expression of nuclear-encoded proteins is regulated at multiple levels, as indicated by transcript and protein profiling in LTR mutants.