Two closely related genes of Arabidopsis encode plastidial cytidinediphosphate diacylglycerol synthases essential for photoautotrophic growth.
Cytidinediphosphate diacylglycerol synthase (CDS) catalyzes the formation of cytidinediphosphate diacylglycerol, an essential precursor of anionic phosphoglycerolipids like phosphatidylglycerol or -inositol. In plant cells, CDS isozymes are located in plastids, mitochondria, and microsomes. Here, we show that these isozymes are encoded by five genes in Arabidopsis (Arabidopsis thaliana). Alternative translation initiation or alternative splicing of CDS2 and CDS4 transcripts can result in up to 10 isoforms. Most of the cDNAs encoding the various plant isoforms were functionally expressed in yeast and rescued the nonviable phenotype of the mutant strain lacking CDS activity. The closely related genes CDS4 and CDS5 were found to encode plastidial isozymes with similar catalytic properties. Inactivation of both genes was required to obtain Arabidopsis mutant lines with a visible phenotype, suggesting that the genes have redundant functions. Analysis of these Arabidopsis mutants provided further independent evidence for the importance of plastidial phosphatidylglycerol for structure and function of thylakoid membranes and, hence, for photoautotrophic growth.
Haselier
André
A
Unit of Botany, Institute for Biology I , Rheinisch-Westfälische Technische Hochschule Aachen University, 52056 Aachen, Germany. haselier@bio1.rwth-aachen.de
Akbari
Hana
H
Weth
Agnes
A
Baumgartner
Werner
W
Frentzen
Margrit
M
D000483:Alleles; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development* / Q000648:ultrastructure; D052818:Autotrophic Processes / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects*; D004269:DNA, Bacterial / Q000235:genetics; D002798:Diacylglycerol Cholinephosphotransferase / Q000235:genetics* / Q000378:metabolism; D017343:Genes, Plant / Q000235:genetics*; D005816:Genetic Complementation Test; D020404:Glycerophospholipids / Q000096:biosynthesis; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008027:Light; D008563:Membrane Lipids / Q000378:metabolism; D016254:Mutagenesis, Insertional / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D018087:Plastids / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects / Q000648:ultrastructure; D021381:Protein Transport / Q000187:drug effects / Q000528:radiation effects; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology / Q000528:radiation effects; D013395:Sucrose / Q000494:pharmacology
D004269:DNA, Bacterial; D020404:Glycerophospholipids; D007527:Isoenzymes; D008563:Membrane Lipids; C036483:T-DNA; D013395:Sucrose; D002798:Diacylglycerol Cholinephosphotransferase