A eukaryotic factor required for accumulation of the chloroplast NAD(P)H dehydrogenase complex in Arabidopsis
A eukaryotic factor required for accumulation of the chloroplast NAD(P)H dehydrogenase complex in Arabidopsis
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DOI：
10.1104/pp.106.088682
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发表时间：
2006-12-01
期刊：
影响因子：
7.4
通讯作者：
Shikanai, Toshiharu
中科院分区：
文献类型：
--
作者：
Muraoka, Ryohei;Okuda, Kenji;Shikanai, Toshiharu
叶绿体中的NAD(P)H脱氢酶(NDH)复合体介导光系统I循环和氯呼吸电子传递。目前已鉴定出11个叶绿体基因和3个核基因编码NDH亚基，但整个亚基组成尚不清楚。一个拟南芥(Arabiopsis Thaliana)氯呼吸减少(Crr3)突变体被分离出来，因为它在光化光照后缺乏瞬时的叶绿素荧光增强；这是由于NDH复合体积累的一个特殊缺陷。CRR3基因(At2g01590)编码一个新的蛋白，该蛋白含有一个可能的胞质靶向信号和一个跨膜结构域。与基因结构一致，CRR3定位于叶绿体的膜部分。除了CRR3稳定NDH复合体的基本功能外，NDH复合体也是CRR3积累所必需的。这些结果表明，CRR3与类囊体膜上的NDH复合体相互作用。与叶绿体NDH复合体中的其他亚基不同，CRR3在蓝藻中不是保守的，而叶绿体NDH复合体被认为是起源的。我们认为CRR3是NDH复合体的一个亚基，它是叶绿体所特有的。
The NAD(P) H dehydrogenase (NDH) complex in chloroplasts mediates photosystem I cyclic and chlororespiratory electron transport. Eleven chloroplast genes and three nuclear genes have been identified as encoding Ndh subunits, but the entire subunit composition is still unknown. An Arabidopsis (Arabidopsis thaliana) chlororespiratory reduction (crr3) mutant was isolated based on its lack of transient increase in chlorophyll fluorescence after actinic light illumination; this was due to a specific defect in accumulation of the NDH complex. The CRR3 gene (At2g01590) encodes a novel protein containing a putative plastid-targeting signal and a transmembrane domain. Consistent with the gene structure, CRR3localized to the membrane fraction of chloroplasts. In addition to the essential function of CRR3 in stabilizing the NDH complex, the NDH complex is also required for the accumulation of CRR3. These results suggest thatCRR3 interacts with theNDHcomplex in the thylakoid membrane. In contrast to other subunits in the chloroplast NDH complex, CRR3 is not conserved in cyanobacteria from which the chloroplast NDH complex is believed to have originated. We propose that CRR3 is a subunit of the NDH complex, which is specific to the chloroplast.