Metabolic Control of Two Dynamic Pools of Diacylglycerol in Budding Yeast

The location of lipids and their distributions across cellular membranes have critical biological consequences, particularly for lipids involved in cellular signaling. In this study, diacylglycerol pools were monitored in budding yeast under conditions where lipid homeostasis was altered. Two predominant pools of diacylglycerol were visualized using the C1 domain of mammalian PKCδ fused to GFP. One pool was associated with vacuolar membranes and the other localized to sites of polarized growth. Upon growth resumption, diacylglycerol pools appeared more dynamic than those of phosphatidic acid and phosphatidylserine. During this period, diacylglycerol enriched puncta and vacuolar rings experienced constant morphological changes with clusters of lipid droplets closely attached. Lack of conversion of diacylglycerol to phosphatidate by Dgk1 led to the accumulation of diacylglycerol in a vacuolar associated compartment. Diacylglycerol distribution was strongly affected in cells lacking the phosphatidylserine synthase Cho1/Pss1. Supplementation of lysophosphatidylserine to cho1 cells did not correct mislocalization of DAG, pointing to a role for phosphatidylserine synthesis and traffic in the establishment of cellular diacylglycerol pools. Support or Funding Information This work was supported by a National Science and Engineering Research Council of Canada to M.R. Terebiznik and V. Zaremberg. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .