title: Storage lipid synthesis is necessary for autophagy induced by nitrogen starvation.
abstract: Nitrogen starvation is a universal stimulus of autophagy. At present, little is known about the relationship between carbon metabolism and autophagy under nitrogen starvation. Here, we show that yeast cells continue to consume glucose and downregulate fermentation under nitrogen starvation. Storage lipid production is increased, with concurrent proliferation of lipid droplets. Furthermore, we provide evidence that triacylglycerol synthesis is crucial for autophagosome biogenesis. It is involved in a step downstream of PAS (phagophore assembly site) scaffold assembly, and upstream of the recruitment of Atg1, Atg14, Atg5 and Atg8. Finally, we demonstrate that lipid droplets transiently interact with Atg8-containing membranes. Our study reveals a novel connection linking neutral lipid metabolism, lipid droplets and autophagy.
authors.affiliation: School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Jing-Zhen
authors.initials: JZ
authors.lastname: Song
authors.affiliation: School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Shan
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing, PR China.
authors.forename: Yongheng
authors.initials: Y
authors.lastname: Liang
authors.affiliation: School of Life Sciences, Tsinghua University, Beijing, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.affiliation: School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China. Electronic address: zxie@sjtu.edu.cn.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Xie
mesh_terms: D001343:Autophagy; D050356:Lipid Metabolism; D008055:Lipids / Q000096:biosynthesis*; D009584:Nitrogen / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D008055:Lipids; D029701:Saccharomyces cerevisiae Proteins; D009584:Nitrogen
keywords: Autophagy; Glucose; Lipid droplet; Nitrogen starvation; Triacylglycerol; Yeast