The Photosystem II Light-Harvesting Protein Lhcb3 Affects the Macrostructure of Photosystem II and the Rate of State Transitions in Arabidopsis
The Photosystem II Light-Harvesting Protein Lhcb3 Affects the Macrostructure of Photosystem II and the Rate of State Transitions in Arabidopsis
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DOI：
10.1105/tpc.108.064006
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发表时间：
2009-10-01
期刊：
影响因子：
11.6
通讯作者：
Jansson, Stefan
中科院分区：
文献类型：
--
作者：
Damkjaer, Jakob T.;Kereiche, Sami;Jansson, Stefan
高等植物的主要三聚体捕光复合物（LHCII）由三种不同的Lhcb蛋白（Lhcb 1 -3）组成。我们发现，拟南芥T-DNA敲除植物缺乏Lhcb 3（koLhcb 3）补偿Lhcb 3的缺乏，产生增加量的Lhcb 1和Lhcb 2。与野生型植物一样，LHCII-光系统II（PSII）超复合物存在于Lhcb 3敲除植物（koLhcb 3）中，LHCII三聚体（M三聚体）的保存表明M三聚体中的Lhcb 3已被Lhcb 1和/或Lhcb 2取代。然而，M LHCII三聚体的旋转位置被改变，表明Lhcb 3亚基影响LHCII天线的宏观结构排列。Lhcb 3的情况下没有导致任何显着的改变PSII效率或QE类型的非光化学猝灭，但从状态1到状态2的过渡率增加koLhcb 3，虽然最终的状态过渡程度不变。在状态1和状态2中，与野生型植物相比，koLhcb 3植物中LHCII的磷酸化水平增加。在koLhcb 3中，从状态1过渡到状态2时磷酸化的相对增加也显著更高。这表明Lhcb 3的主要功能是调节状态转换的速率。
The main trimeric light-harvesting complex of higher plants (LHCII) consists of three different Lhcb proteins (Lhcb1-3). We show that Arabidopsis thaliana T-DNA knockout plants lacking Lhcb3 (koLhcb3) compensate for the lack of Lhcb3 by producing increased amounts of Lhcb1 and Lhcb2. As in wild-type plants, LHCII-photosystem II (PSII) supercomplexes were present in Lhcb3 knockout plants (koLhcb3), and preservation of the LHCII trimers (M trimers) indicates that the Lhcb3 in M trimers has been replaced by Lhcb1 and/or Lhcb2. However, the rotational position of the M LHCII trimer was altered, suggesting that the Lhcb3 subunit affects the macrostructural arrangement of the LHCII antenna. The absence of Lhcb3 did not result in any significant alteration in PSII efficiency or qE type of nonphotochemical quenching, but the rate of transition from State 1 to State 2 was increased in koLhcb3, although the final extent of state transition was unchanged. The level of phosphorylation of LHCII was increased in the koLhcb3 plants compared with wild-type plants in both State 1 and State 2. The relative increase in phosphorylation upon transition from State 1 to State 2 was also significantly higher in koLhcb3. It is suggested that the main function of Lhcb3 is to modulate the rate of state transitions.