title: Extraplastidial cytidinediphosphate diacylglycerol synthase activity is required for vegetative development in Arabidopsis thaliana.
abstract: Cytidinediphosphate diacylglycerol synthase (CDS) catalyzes the activation of phosphatidic acid to cytidinediphosphate (CDP)-diacylglycerol, a central intermediate in glycerolipid biosynthesis in prokaryotic and eukaryotic organisms. Cytidinediphosphate-diacylglycerol is the precursor to phosphatidylinositol, phosphatidylglycerol (PG) and cardiolipin of eukaryotic phospholipids that are essential for various cellular functions. Isoforms of CDS are located in plastids, mitochondria and the endomembrane system of plants and are encoded by five genes in Arabidopsis. Two genes have previously been shown to code for the plastidial isoforms which are indispensable for the biosynthesis of plastidial PG, and thus biogenesis and function of thylakoid membranes. Here we have focused on the extraplastidial CDS isoforms, encoded by CDS1 and CDS2 which are constitutively expressed contrary to CDS3. We provide evidence that these closely related CDS genes code for membrane proteins located in the endoplasmic reticulum and possess very similar enzymatic properties. Development and analysis of Arabidopsis mutants lacking either one or both CDS1 and CDS2 genes clearly shows that these two genes have redundant functions. As reflected in the seedling lethal phenotype of the cds1cds2 double mutant, plant cells require at least one catalytically active microsomal CDS isoform for cell division and expansion. According to the altered glycerolipid composition of the double mutant in comparison with wild-type seedlings, it is likely that the drastic decrease in the level of phosphatidylinositol and the increase in phosphatidic acid cause defects in cell division and expansion.
authors.affiliation: Unit of Botany, Institute for Biology I, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Helga
authors.initials: H
authors.lastname: Peisker
authors.forename: Agnes
authors.initials: A
authors.lastname: Weth
authors.forename: Werner
authors.initials: W
authors.lastname: Baumgartner
authors.forename: Peter
authors.initials: P
authors.lastname: Dörmann
authors.forename: Margrit
authors.initials: M
authors.lastname: Frentzen
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002798:Diacylglycerol Cholinephosphotransferase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004075:Diglycerides; D050356:Lipid Metabolism / Q000235:genetics; D009154:Mutation; D009713:Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010641:Phenotype; D010716:Phosphatidylinositols; D018087:Plastids; D036226:Seedlings / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D020524:Thylakoids
chemical_list: C011439:1,2-diacylglycerol; D029681:Arabidopsis Proteins; D004075:Diglycerides; D010716:Phosphatidylinositols; D009713:Nucleotidyltransferases; C022348:phosphatidate cytidylyltransferase; D002798:Diacylglycerol Cholinephosphotransferase
keywords: Arabidopsis; cytidinediphosphate diacylglycerol synthase; membrane lipid composition; phosphatidylglycerol; phosphatidylinositol; seedling lethal