The yeast, Saccharomyces cerevisiae serves as a model eukaryote to study the regulation of phospholipid metabolism/signaling. Diacylglycerol pyrophosphate (DGPP) is a minor phospholipid in yeast that is synthesized from phosphatidate (PA) via the reaction catalyzed by the membrane-associated enzyme PA kinase and is dephosphorylated to PA, and then to diacylglycerol via the reactions catalyzed by the vacuolar membrane-associated DPPI-encoded DGPP phosphatase. The major hypothesis of the work proposed in this application is that DGPP and/or its metabolism plays a role in cellular responses to the stress conditions of zinc deprivation and to oxidative damage in sodM mutants defective in the copper/zinc superoxide dismutase. The DPPI gene is induced by zinc deprivation and is coordinately regulated with other genes in the S. cerevisiae genome that control zinc homeostasis. We propose to examine the hypothesis that the DGPP phosphatase enzyme, whose enzymatic function controls the cellular levels of DGPP and PA, as well as phosphatidylinositol, plays a role in the regulation of phospholipid metabolism/signaling in vacuolar membranes in response to zinc deprivation. We hypothesize that the function of DGPP phosphatase in the vacuolar membrane may be related to functions associated with the copper/zinc superoxide dismutase. Regulation of DGPP phosphatase will be examined in sodldelta mutant cells. The effects of the dppldelta mutation and the overexpression of DGPP phosphatase will be examined in sod1delta mutant cells. Regulation of DGPP phosphatase by phosphorylation via protein kinase A will be examined, and mutant(s) defective in phosphorylation will be used to examine the relevance of DGPP phosphatase phosphorylation in response to stress. The gene encoding PA kinase will be isolated, and a mutant will be constructed and characterized with respect to PA kinase function in response to the stress conditions that regulate DGPP phosphatase. The regulation of PA kinase expression and activity will also be examined. PA kinase will be purified and characterized, and the regulation of activity by phospholipids and water-soluble metabolites will be investigated.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM028140-23
Application #
6829131
Study Section
Medical Biochemistry Study Section (MEDB)
Program Officer
Chin, Jean
Project Start
1980-07-01
Project End
2006-06-30
Budget Start
2005-01-01
Budget End
2006-06-30
Support Year
23
Fiscal Year
2005
Total Cost
$325,792
Indirect Cost
Name
Rutgers University
Department
Nutrition
Type
Schools of Earth Sciences/Natur
DUNS #
001912864
City
New Brunswick
State
NJ
Country
United States
Zip Code
08901
Carman, George M; Han, Gil-Soo (2018) Phosphatidate phosphatase regulates membrane phospholipid synthesis via phosphatidylserine synthase. Adv Biol Regul 67:49-58
Park, Yeonhee; Han, Gil-Soo; Carman, George M (2017) A conserved tryptophan within the WRDPLVDID domain of yeast Pah1 phosphatidate phosphatase is required for its in vivo function in lipid metabolism. J Biol Chem 292:19580-19589
Hassaninasab, Azam; Han, Gil-Soo; Carman, George M (2017) Tips on the analysis of phosphatidic acid by the fluorometric coupled enzyme assay. Anal Biochem 526:69-70
Dey, Prabuddha; Su, Wen-Min; Han, Gil-Soo et al. (2017) Phosphorylation of lipid metabolic enzymes by yeast protein kinase C requires phosphatidylserine and diacylglycerol. J Lipid Res 58:742-751
Han, Gil-Soo; Carman, George M (2017) Yeast PAH1-encoded phosphatidate phosphatase controls the expression of CHO1-encoded phosphatidylserine synthase for membrane phospholipid synthesis. J Biol Chem 292:13230-13242
Qiu, Yixuan; Hassaninasab, Azam; Han, Gil-Soo et al. (2016) Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae. J Biol Chem 291:26455-26467
Park, Ki-Sook; Dubon, Maria Jose; Gumbiner, Barry M (2015) N-cadherin mediates the migration of MCF-10A cells undergoing bone morphogenetic protein 4-mediated epithelial mesenchymal transition. Tumour Biol 36:3549-56
Barneda, David; Planas-Iglesias, Joan; Gaspar, Maria L et al. (2015) The brown adipocyte protein CIDEA promotes lipid droplet fusion via a phosphatidic acid-binding amphipathic helix. Elife 4:e07485
Hsieh, Lu-Sheng; Su, Wen-Min; Han, Gil-Soo et al. (2015) Phosphorylation regulates the ubiquitin-independent degradation of yeast Pah1 phosphatidate phosphatase by the 20S proteasome. J Biol Chem 290:11467-78
Park, Yeonhee; Han, Gil-Soo; Mileykovskaya, Eugenia et al. (2015) Altered Lipid Synthesis by Lack of Yeast Pah1 Phosphatidate Phosphatase Reduces Chronological Life Span. J Biol Chem 290:25382-94

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