Schizosaccharomyces pombe cells deficient in triacylglycerols synthesis undergo apoptosis upon entry into the stationary phase.
Triacylglycerols (TAG) are important energy storage molecules for nearly all eukaryotic organisms. In this study, we found that two gene products (Plh1p and Dga1p) are responsible for the terminal step of TAG synthesis in the fission yeast Schizosaccharomyces pombe through two different mechanisms: Plh1p is a phospholipid diacylglycerol acyltransferase, whereas Dga1p is an acyl-CoA:diacylglycerol acyltransferase. Cells with both dga1+ and plh1+ deleted (DKO cells) lost viability upon entry into the stationary phase and demonstrated prominent apoptotic markers. Exponentially growing DKO cells also underwent dramatic apoptosis when briefly treated with diacylglycerols (DAGs) or free fatty acids. We provide strong evidence suggesting that DAG, not sphingolipids, mediates fatty acids-induced lipoapoptosis in yeast. Lastly, we show that generation of reactive oxygen species is essential to lipoapoptosis.
Zhang
Qian
Q
Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore 119260, Republic of Singapore.
Chieu
Hai Kee
HK
Low
Choon Pei
CP
Zhang
Shaochong
S
Heng
Chew Kiat
CK
Yang
Hongyuan
H
D000217:Acyltransferases; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle; D004075:Diglycerides / Q000494:pharmacology; D005227:Fatty Acids / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology* / Q000378:metabolism; D014280:Triglycerides / Q000096:biosynthesis / Q000172:deficiency*
D004075:Diglycerides; D005227:Fatty Acids; D017382:Reactive Oxygen Species; D014280:Triglycerides; D000217:Acyltransferases