Fungi contain a group of phosphoinositol containing sphingolipids not found in higher animals. These lipids provide a logical focus for the rational design of antifungal agents for use in alleviating human fungal infections. The long term objectives of the proposed research with S. cerevisiae is to define in some detail the metabolic pathways associated with the synthesis and degradation of these lipids and to define the biological function(s) of these compounds. Recently developed high resolution separation methods will be applied to in vivo pulse-chase studies of the incorporation and turnover of radioactive precursors into the phosphosphingolipids of yeast. Individual synthetic steps will be studied in vitro with enzyme preparations derived from yeast membranes. A group of recently isolated yeast mutants that require a long chain base for growth will be employed to define the genes responsible for this auxotrophy and to define the role of each gene in sphingolipid metabolism. These mutants will also be studied as long chain base starvation progresses to discover changes in normal biochemical processes that may give insight into the function(s) of sphingolipids.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI020600-04
Application #
3130342
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1983-12-01
Project End
1988-11-30
Budget Start
1986-12-01
Budget End
1987-11-30
Support Year
4
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of Kentucky
Department
Type
Schools of Medicine
DUNS #
832127323
City
Lexington
State
KY
Country
United States
Zip Code
40506
Lester, R L; Dickson, R C (1993) Sphingolipids with inositolphosphate-containing head groups. Adv Lipid Res 26:253-74
Patton, J L; Srinivasan, B; Dickson, R C et al. (1992) Phenotypes of sphingolipid-dependent strains of Saccharomyces cerevisiae. J Bacteriol 174:7180-4
Patton, J L; Lester, R L (1992) Phosphatidylinositol phosphate, phosphatidylinositol bisphosphate, and the phosphoinositol sphingolipids are found in the plasma membrane and stimulate the plasma membrane H(+)-ATPase of Saccharomyces cerevisiae. Arch Biochem Biophys 292:70-6
Pinto, W J; Srinivasan, B; Shepherd, S et al. (1992) Sphingolipid long-chain-base auxotrophs of Saccharomyces cerevisiae: genetics, physiology, and a method for their selection. J Bacteriol 174:2565-74
Pinto, W J; Wells, G W; Lester, R L (1992) Characterization of enzymatic synthesis of sphingolipid long-chain bases in Saccharomyces cerevisiae: mutant strains exhibiting long-chain-base auxotrophy are deficient in serine palmitoyltransferase activity. J Bacteriol 174:2575-81
Patton, J L; Lester, R L (1991) The phosphoinositol sphingolipids of Saccharomyces cerevisiae are highly localized in the plasma membrane. J Bacteriol 173:3101-8
Buede, R; Rinker-Schaffer, C; Pinto, W J et al. (1991) Cloning and characterization of LCB1, a Saccharomyces gene required for biosynthesis of the long-chain base component of sphingolipids. J Bacteriol 173:4325-32
Dickson, R C; Wells, G B; Schmidt, A et al. (1990) Isolation of mutant Saccharomyces cerevisiae strains that survive without sphingolipids. Mol Cell Biol 10:2176-81