Topic
Diacylglycerol kinase
About: Diacylglycerol kinase is a research topic. Over the lifetime, 6442 publications have been published within this topic receiving 325510 citations.
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3,341 citations
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3,110 citations
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TL;DR: Evidence is provided that the rapid 32P-PtdOH response was primarily generated through DAG kinase (DGK), and a tentative model illustrating direct cold effects on phospholipid metabolism is presented.
Abstract: Phosphatidic acid (PtdOH) is emerging as an important signalling lipid in abiotic stress responses in plants. The effect of cold stress was monitored using 32P-labelled seedlings and leaf discs of Arabidopsis thaliana. Low, non-freezing temperatures were found to trigger a very rapid 32P-PtdOH increase, peaking within 2 and 5 min, respectively. In principle, PtdOH can be generated through three different pathways, i.e. i) via de novo phospholipid biosynthesis (through acylation of lyso-PtdOH), ii) via phospholipase D hydrolysis of structural phospholipids or iii) via phosphorylation of diacylglycerol (DAG) by DAG kinase (DGK). Using a differential 32P-labelling protocol and a PLD-transphosphatidylation assay, evidence is provided that the rapid 32P-PtdOH response was primarily generated through DGK. A simultaneous decrease in the levels of 32P-PtdInsP, correlating in time, temperature dependency and magnitude with the increase in 32P-PtdOH, suggested that a PtdInsP-hydrolyzing PLC generated the DAG in this reaction. Testing T-DNA insertion lines available for the seven DGK genes, revealed no clear changes in 32P-PtdOH responses, suggesting functional redundancy. Similarly, known cold-stress mutants were analyzed to investigate whether the PtdOH response acted downstream of the respective gene products. The hos1, los1 and fry1 mutants were found to exhibit normal PtdOH responses. Slight changes were found for ice1, snow1, and the overexpression line Super-ICE1, however, this was not cold-specific and likely due to pleiotropic effects. A tentative model illustrating direct cold effects on phospholipid metabolism is presented.
1,936 citations
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TL;DR: Multiple receptor pathways feeding into multiple lipid pathways have the common end result of activating protein kinase C by production of its second messenger, diacylglycerol.
1,678 citations
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TL;DR: The hypothesis that an increase in plasma fatty acid concentration results in a increase in intracellular fatty acyl-CoA and DAG concentrations, which results in activation of PKC-θ leading to increased IRS-1 Ser307 phosphorylation is supported.
1,562 citations