The effective flux between phospholipids and neutral lipids is critical for a high level of the biosynthesis and accumulation of very long chain polyunsaturated fatty acids (VLCPUFAs) such as arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). Here we describe a cDNA (PiCPT1) from Phytophthora infestans, a VLCPUFA-producing oomycete that may have a role in acyl trafficking between diacylglycerol (DAG) and phosphatidylcholine (PC) during the biosynthesis of VLCPUFAs. The cDNA encodes a polypeptide of 393 amino acids with a conserved CDP-alcohol phosphotransferase motif and approximately 27% of amino acid identity to the yeast Saccharomyces cerevisiae cholinephosphotransferase (ScCPT1). In vitro assays indicate PiCPT1 has high cholinephosphotransferase (CPT) activity, but not any ethanolaminephosphotransferase (EPT) activity. Substrate specificity assays show that it prefers VLCPUFA-containing DAGs such as ARA-DAG and DHA-DAG as substrates. Real-time PCR analysis reveals that expression of PiCPT1 was up-regulated in P. infestans when fed with exogenous VLCPUFAs. These results lead us to conclude that PiCPT1 is a VLCPUFA-specific CPT which may play an important role in shuffling VLCPUFAs from DAG to PC in the biosynthesis of VLCPUFAs in P. infestans.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|