Lipid droplets maintain lipid homeostasis during anaphase for efficient cell separation in budding yeast.
The neutral lipids steryl ester and triacylglycerol (TAG) are stored in the membrane-bound organelle lipid droplet (LD) in essentially all eukaryotic cells. It is unclear what physiological conditions require the mobilization or storage of these lipids. Here, we study the budding yeast mutant are1Δ are2Δ dga1Δ lro1Δ, which cannot synthesize the neutral lipids and therefore lacks LDs. This quadruple mutant is delayed at cell separation upon release from mitotic arrest. The cells have abnormal septa, unstable septin assembly during cytokinesis, and prolonged exocytosis at the division site at the end of cytokinesis. Lipidomic analysis shows a marked increase of diacylglycerol (DAG) and phosphatidic acid, the precursors for TAG, in the mutant during mitotic exit. The cytokinesis and separation defects are rescued by adding phospholipid precursors or inhibiting fatty acid synthesis, which both reduce DAG levels. Our results suggest that converting excess lipids to neutral lipids for storage during mitotic exit is important for proper execution of cytokinesis and efficient cell separation.
Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan.
Po-Lin
PL
Yang
Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan.
Tzu-Han
TH
Hsu
Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan reyhuei@gate.sinica.edu.tw cwwang02@gate.sinica.edu.tw.
Chao-Wen
CW
Wang
Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan reyhuei@gate.sinica.edu.tw cwwang02@gate.sinica.edu.tw.
Rey-Huei
RH
Chen
D000705:Anaphase; D002453:Cell Cycle; D002469:Cell Separation; D048749:Cytokinesis / Q000502:physiology; D004075:Diglycerides / Q000378:metabolism; D006706:Homeostasis / Q000502:physiology; D066292:Lipid Droplets / Q000378:metabolism* / Q000502:physiology; D050356:Lipid Metabolism / Q000502:physiology; D010712:Phosphatidic Acids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D004718:Saccharomycetales / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism
C011439:1,2-diacylglycerol; D004075:Diglycerides; D010712:Phosphatidic Acids; D010743:Phospholipids; D029701:Saccharomyces cerevisiae Proteins; D014280:Triglycerides