| Abstrakt: |
Synthesis, storage and degradation of neutral lipids enable cells to continue cell metabolism when nutrients are no longer provided by the environment. Major neutral lipids occurring in yeast are triacylglycerols and steryl esters. These hydrophobic molecules are sequestered from the cytosolic environment in the core of so-called lipid particles (lipid droplets). When nutrients are no longer provided by the environment, hydrolytic enzymes catalyze the degradation of triacylglycerols and steryl esters. The respective breakdown products serve as energy source and/or building blocks for membrane formation. Here, enzymes catalyzing neutral lipid synthesis and degradation in the budding yeast Saccharomyces cerevisiae are described with special emphasis to their localization and regulation. Formation of lipid particles is not only disturbed in cells defective in polypeptides directly involved in neutral lipid synthesis and degradation but also in a number of mutants defective in pathways which are not obviously linked to neutral lipid turnover. Although research over the past decade provided major insights into neutral lipid metabolism, many aspects of neutral lipid synthesis, storage and degradation remain to be elucidated. Research needs for a better understanding of neutral lipid turnover are outlined at the end of this chapter. [ABSTRACT FROM AUTHOR] |
