title: CDP1, a novel component of chloroplast division site positioning system in Arabidopsis.
abstract: 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 cdp1 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.
authors: College of Life Science, Capital Normal University, Beijing, China.
authors: Min
authors: M
authors: Zhang
authors: Yong
authors: Y
authors: Hu
authors: Jingjing
authors: J
authors: Jia
authors: Dapeng
authors: D
authors: Li
authors: Runjie
authors: R
authors: Zhang
authors: Hongbo
authors: H
authors: Gao
authors: Yikun
authors: Y
authors: He
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D002736:Chloroplasts / Q000378:metabolism* / Q000648:ultrastructure; D009154:Mutation; D010641:Phenotype; D030821:Plants, Genetically Modified / Q000378:metabolism
chemical_list: C493630:ARC3 protein, Arabidopsis; C502272:ARC6 protein, Arabidopsis; D029681:Arabidopsis Proteins