摘要
叶绿体是从 endosymbiotic cyanobacteria 演变的植物特定的细胞器。他们通过二进制分裂划分。叶绿体部门地点的选择为对称的叶绿体部门是枢轴的。在 E。coli，在房间的中点部门地点放被 Min 系统的动态摆动调整，它包括 MinC，头脑和矿。在植物的头脑和矿的相当或相同的事物涉及叶绿体分割。MinC 的相当或相同的事物仍然没在更高的植物被识别。然而，象 FtsZ 一样蛋白质， ARC3，被发现地点放涉及叶绿体分割。这里，我们报导放 1 的那个叶绿体部门地点(AtCDP1 ) 是在 Arabidopsis 涉及叶绿体部门地点放置的新奇叶绿体部门蛋白质。AtCDP1 被与房间部门显型为殖民地在细菌屏蔽一个 Arabidopsis cDNA 表示图书馆发现。AtCDP1 只在 Arabidopsis 在年轻绿纸巾被表示。有多重部门地点的伸长的叶绿体在 loss-of-function cdp1 异种被观察。AtCDP1 的 Overexpression 也引起了一个叶绿体部门显型。蛋白质相互作用试金建议 AtCDP1 可以调停通过和 ARC3 的相互作用放的叶绿体部门地点。总的来说，我们的结果显示 AtCDP1 是放系统，和这个系统的工作机制的叶绿体部门地点的一个新奇部件与在原核生物的房间的传统的 MinCDE 系统的不同。
Chloroplasts are plant-specific organelles that evolved from endosymbiotic cyanobacteria. They divide through binary fission. Selection of the chloroplast division site is pivotal for the symmetric chloroplast division. In E. coli, positioning of the division site at the midpoint of the cell is regulated by dynamic oscillation of the Min system, which includes MinC, MinD and MinE. Homologs of MinD and MinE in plants are involved in chloroplast division. The homolog of MinC still has not been identified in higher plants. However, an FtsZ-like protein, ARC3, was found to be involved in chloroplast division site positioning. Here, we report that chloroplast division site positioning 1 （AtCDP1） is a novel chloroplast division protein involved in chloroplast division site placement in Arabidopsis. AtCDP1 was discovered by screening an Arabidopsis cDNA expression library in bacteria for colonies with a cell division phenotype. AtCDP1 is exclusively expressed in young green tissues in Arabidopsis. Elongated chloroplasts with multiple division sites were observed in the loss-of-function cdpl mutant. Overexpression of AtCDP1 caused a chloroplast division phenotype too. Protein interaction assays suggested that AtCDP1 may mediate the chloroplast division site positioning through the interaction with ARC3. Overall, our results indicate that AtCDP1 is a novel component of the chloroplast division site positioning system, and the working mechanism of this system is different from that of the traditional MinCDE system in prokaryotic cells.
基金
Acknowledgment We thank the Arabidopsis Biological Resource Center （Ohio State University, Columbus） for providing the Arabidopsis seeds and the editor for was supported by careful reading of the manuscript. This work the National Natural Science Foundation of China （30470879） and Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality to He, and National Natural Science Foundation of China （30500288） and Science and Technology Development Program of Beijing Municipal Education Committee grant （KM200610028010） of Beijing Education Committee to Hu.
