Increase in cellular triacylglycerol content and emergence of large ER-associated lipid droplets in the absence of CDP-DG synthase function.
Bottom Line: Using two species of fission yeast, we show that cycling cells deficient in the function of the ER-resident CDP-DG synthase Cds1 exhibit markedly increased triacylglycerol content and assemble large lipid droplets closely associated with the ER membranes.We demonstrate that these unusual structures recruit the triacylglycerol synthesis machinery and grow by expansion rather than by fusion.Our results suggest that interfering with the CDP-DG route of phosphatidic acid utilization rewires cellular metabolism to adopt a triacylglycerol-rich lifestyle reliant on the Kennedy pathway.
Affiliation: Temasek Life Sciences Laboratory, 117604 Singapore Department of Biological Sciences, National University of Singapore, 117543 Singapore.Show MeSH
Mentions: It was previously shown that the loss of the Cds1 function in budding yeast triggered an approximately twofold increase in the cellular amount of its substrate PA (Fei et al., 2011). We did not observe an increase in cellular PA levels in S. japonicus cells deficient in Cds1 function (Figure 4A). However, we detected a noticeable increase in the levels of diacylglycerols in these cells, likely due to rapid dephosphorylation of available PA (Figure 4B and Supplemental Figure S4).
Affiliation: Temasek Life Sciences Laboratory, 117604 Singapore Department of Biological Sciences, National University of Singapore, 117543 Singapore.