The membrane-associated phospholipid biosynthetic enzymes are important because their activities are involved in structural as well as functional properties of cell membranes. In the yeast Saccharomyces cerevisiae the enzyme activities in the reaction sequence phosphatidic acid - greater than CDP-diacylglycerol - greater than phosphatidylserine - greater than phosphatidylethanolamine - greater than phosphatidylmonomethylethanolamine - greater than phosphatidyldimethylethanolamine - greater phosphatidylcholine are coordinately regulated to the synthesis of phosphatidylinositol. This application will focus on the regulation of four of the enzyme activities in this pathway, namely, CDP-diacylglycerol synthase, phosphatidylserine synthase, phosphatidylinositol synthase, and the phospholipid N-methyltransferases. CDP-diacylglycerol synthase and the phospholipid N-methyltransferases will be purified to homogeneity and will be characterized with respect to enzymological, chemical, and physical properties. Purified preparations of phosphatidylserine synthase and phosphatidylinositol synthase are already available for the project. The purified enzymes will be reconstituted into well defined unilamellar phospholipid vesicles to study activity modulation by phospholipids, water-soluble metabolites, and by phosphorylation/dephosphorylation. Antibodies specific for each of the enzymes will be prepared and used as probes to study the regulation of enzyme formation in wild type and mutant strains of S. cerevisiae grown under various conditions. Enzyme regulation will also be studied in clones containing the structural genes encoding for these enzymes. The results found with S. cerevisiae should be relevant to higher eucaryotic organisms.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM028140-07
Application #
3275399
Study Section
Biochemistry Study Section (BIO)
Project Start
1980-07-01
Project End
1992-03-31
Budget Start
1987-04-01
Budget End
1988-03-31
Support Year
7
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Rutgers University
Department
Type
Earth Sciences/Resources
DUNS #
038633251
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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