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Transcriptional regulation of the yeast TGL3 ‐encoded triacylglycerol lipase
Author(s) -
Lu Chieh,
Ye BoHong,
Su WenMin
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.488.10
Subject(s) - biochemistry , diacylglycerol kinase , lipase , fatty acid , lipid metabolism , chemistry , saccharomyces cerevisiae , biology , yeast , enzyme , microbiology and biotechnology , protein kinase c
The yeast TGL3 ‐encoded triacylglycerol (TAG) lipase catalyzes the hydrolytic reaction of TAG yielding fatty acid and diacylglycerol (DAG). The reaction products DAG and fatty acid not only can be used as building blocks for the synthesis of phospholipids, but also serve as lipid signaling molecules. In addition, fatty acid can undergo β‐oxidation to generate ATP. During growth resumption, the stored TAG in lipid droplet is rapidly hydrolyzed by Tgl3 to provide precursors for membrane phospholipids and to generate lipid signaling molecules that are essential for normal cell growth and cell cycle progression at the G1/S phase. However, excessed fatty acid and DAG are also detrimental to cell growth as they exhibit detergent‐like properties that can disrupt membrane structure and cause defect in cell integrity. Thus, Tgl3 lipase activity must be tightly controlled and mechanisms of regulation need to be elucidated. In this study, using β‐galactosidase reporter assay, we found a sharp induction of TGL3 expression after cells were transferred into fresh medium from the stationary phase. Maximum expression was observed at first hour where the β‐galactosidase activity was 62% greater than the activity at the stationary phase. Moreover, the TGL3 promoter was shown to interact with the purified Reb1 transcriptional factor in the electrophoretic mobility shift assay. A Reb1 consensus recognition sequence (GGGTAA, −362 to −357) in TGL3 promoter is responsible for its specific binding to the Reb1 protein. The effects of Reb1‐mediated TGL3 regulation on the function of Tgl3 as well as lipid metabolism are currently under investigation using the TGL3 Reb1‐binding site mutations. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .