LOW PSII ACCUMULATION1 is involved in efficient assembly of photosystem II in Arabidopsis thaliana
LOW PSII ACCUMULATION1 is involved in efficient assembly of photosystem II in Arabidopsis thaliana
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DOI：
10.1105/tpc.105.037689
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发表时间：
2006-04-01
期刊：
影响因子：
11.6
通讯作者：
Zhang, LX
中科院分区：
文献类型：
--
作者：
Peng, LW;Ma, JF;Zhang, LX
为了深入了解光系统 II (PSII) 生物发生和维持的过程，我们对拟南芥的低 psii 积累 1 (lpa1) 突变体进行了表征，该突变体的 PSII 复合物积累水平通常低于野生型水平。体内蛋白质标记实验表明，lpa1 突变体中 D1 和 D2 蛋白质的合成大大减少，而其他质体编码蛋白质的翻译速度与野生型相似。此外，lpa1 中 PSII 核心蛋白 CP47、CP43、D1 和 D2 的周转率高于野生型植物。新合成的 PSII 蛋白被组装成功能性蛋白复合物，但在突变体中组装效率较低。 LPA1 编码含有两个四肽重复结构域的叶绿体蛋白，是一种内在膜蛋白，但不是 PSII 的完整亚基。酵母双杂交研究表明，LPA1 与 D1 相互作用，但不与 D2、细胞色素 b6 或 Alb3 相互作用。因此，LPA1 似乎是有效 PSII 组装所需的完整膜伴侣，可能是通过与 PSII 反应中心蛋白 D1 直接相互作用。
To gain insight into the processes involved in photosystem II (PSII) biogenesis and maintenance, we characterized the low psii accumulation1 (lpa1) mutant of Arabidopsis thaliana, which generally accumulates lower than wild-type levels of the PSII complex. In vivo protein labeling experiments showed that synthesis of the D1 and D2 proteins was greatly reduced in the lpa1 mutant, while other plastid-encoded proteins were translated at rates similar to the wild type. In addition, turnover rates of the PSII core proteins CP47, CP43, D1, and D2 were higher in lpa1 than in wild-type plants. The newly synthesized PSII proteins were assembled into functional protein complexes, but the assembly was less efficient in the mutant. LPA1 encodes a chloroplast protein that contains two tetratricopeptide repeat domains and is an intrinsic membrane protein but not an integral subunit of PSII. Yeast two-hybrid studies revealed that LPA1 interacts with D1 but not with D2, cytochrome b6, or Alb3. Thus, LPA1 appears to be an integral membrane chaperone that is required for efficient PSII assembly, probably through direct interaction with the PSII reaction center protein D1.