LPA66 Is Required for Editing psbF Chloroplast Transcripts in Arabidopsis
LPA66 Is Required for Editing psbF Chloroplast Transcripts in Arabidopsis
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DOI：
10.1104/pp.109.136812
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发表时间：
2009-07-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Lixin
中科院分区：
文献类型：
--
作者：
Cai, Wenhe;Ji, Daili;Zhang, Lixin
为了深入了解RNA编辑的分子机制，我们对表现出高叶绿素荧光表型的低PSII积累66(Lpa66)拟南芥突变体进行了表征。其微扰的叶绿素荧光反映在光系统II(PSII)蛋白水平的降低上。体内蛋白质标记显示，与野生型相比，PSII反应中心蛋白D1/D2的合成速率较低，而PSII核心蛋白的周转率较高。新合成的蛋白质组装到PSII中发生在lpa66突变体中，但与野生型相比效率降低。LPA66编码五肽重复序列家族的一个叶绿体蛋白。在lpa66突变体中，将丝氨酸转化为苯丙氨酸的psbF的编辑受到特别的损害。因此，在拟南芥中，LPA66是编辑psbF转录本所特需的，而由于缺乏编辑而导致的氨基酸交替强烈影响PSII复合体的组装效率。
To gain insight into the molecular mechanism of RNA editing, we have characterized the low psii accumulation66 (lpa66) Arabidopsis (Arabidopsis thaliana) mutant, which displays a high chlorophyll fluorescence phenotype. Its perturbed chlorophyll fluorescence is reflected in reduced levels of photosystem II (PSII) proteins. In vivo protein labeling showed that synthesis rates of the PSII reaction center protein D1/D2 were lower, and turnover rates of PSII core proteins higher, than in wild-type counterparts. The assembly of newly synthesized proteins into PSII occurs in the lpa66 mutant but with reduced efficiency compared with the wild type. LPA66 encodes a chloroplast protein of the pentatricopeptide repeat family. In lpa66 mutants, editing of psbF that converts serine to phenylalanine is specifically impaired. Thus, LPA66 is specifically required for editing the psbF transcripts in Arabidopsis, and the amino acid alternation due to lack of editing strongly affects the efficiency of the assembly of PSII complexes.