RPT2/NCH1 subfamily of NPH3-like proteins is essential for the chloroplast accumulation response in land plants
RPT2/NCH1 subfamily of NPH3-like proteins is essential for the chloroplast accumulation response in land plants
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DOI：
10.1073/pnas.1602151113
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发表时间：
2016-09-13
影响因子：
11.1
通讯作者：
Wada, Masamitsu
中科院分区：
文献类型：
--
作者：
Suetsugu, Noriyuki;Takemiya, Atsushi;Wada, Masamitsu
在绿色植物中，蓝光受体激酶趋光素介导各种光变和发育反应，如向光性、叶绿体光迁移(积累和避免)、气孔开放和叶片扁平，从而促进光合作用。在拟南芥中，两种趋光素(Phot1和Pho2)冗余地介导这些反应。NAPH3和RPT2属于BTB结构域蛋白中的NPH3/RPT2-like(NRL)家族中的两个光敏相互作用蛋白，它们介导向光性和叶片扁平。然而，NRL蛋白在叶绿体光迁移运动中的作用仍有待确定。在这里，我们证明了另一种与光敏素相互作用的NRL蛋白，叶绿体运动NRL蛋白1(NCH1)和RPT2冗余地介导叶绿体积累反应，而不是回避反应。NPH3、RPT2和NCH1不参与叶绿体回避反应或气孔开放。在地钱中，NCH1同源基因MpNCH1对叶绿体积累反应是必需的，而不是回避反应，这表明RPT2/NCH1对光敏素介导的叶绿体积累反应的调节在陆地植物中是保守的。因此，NRL蛋白组合可以确定不同的趋光素介导的反应的特异性。
In green plants, the blue light receptor kinase phototropin mediates various photomovements and developmental responses, such as phototropism, chloroplast photorelocation movements (accumulation and avoidance), stomatal opening, and leaf flattening, which facilitate photosynthesis. In Arabidopsis, two phototropins (phot1 and phot2) redundantly mediate these responses. Two phototrop-ininteracting proteins, NONPHOTOTROPIC HYPOCOTYL 3 (NPH3) and ROOT PHOTOTROPISM 2 (RPT2), which belong to the NPH3/RPT2-like (NRL) family of BTB (broad complex, tramtrack, and bric a brac) domain proteins, mediate phototropism and leaf flattening. However, the roles of NRL proteins in chloroplast photorelocation movement remain to be determined. Here, we show that another phototropin-interacting NRL protein, NRL PROTEIN FOR CHLOROPLAST MOVEMENT 1 (NCH1), and RPT2 redundantly mediate the chloroplast accumulation response but not the avoidance response. NPH3, RPT2, and NCH1 are not involved in the chloroplast avoidance response or stomatal opening. In the liverwort Marchantia polymorpha, the NCH1 ortholog, MpNCH1, is essential for the chloroplast accumulation response but not the avoidance response, indicating that the regulation of the phototropin-mediated chloroplast accumulation response by RPT2/NCH1 is conserved in land plants. Thus, the NRL protein combination could determine the specificity of diverse phototropin-mediated responses.