Meyers Alex, Chourey Karuna, Weiskittel Taylor M, Pfiffner Susan, Dunlap John R, Hettich Robert L, Dalhaimer Paul
Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996-2200, USA.
Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
J Microbiol. 2017 Feb;55(2):112-122. doi: 10.1007/s12275-017-6205-1. Epub 2017 Jan 26.
Lipid droplets consist of a core of neutral lipids surrounded by a phospholipid monolayer with bound proteins. Much of the information on lipid droplet function comes from proteomic and lipodomic studies that identify the components of droplets isolated from organisms throughout the phylogenetic tree. Here, we add to that important inventory by reporting lipid droplet factors from the fission yeast, Schizosaccharomyces pombe. Unique to this study was the fact that cells were cultured in three different environments: 1) late log growth phase in glucose-based media, 2) stationary phase in glucosebased media, and 3) late log growth phase in media containing oleic acid. We confirmed colocalization of major factors with lipid droplets using live-cell fluorescent microscopy. We also analyzed droplets from each of the three conditions for sterol ester (SE) and triacylglycerol (TAG) content, along with their respective fatty acid compositions. We identified a previously undiscovered lipid droplet protein, Vip1p, which affects droplet size distribution. The results provide further insight into the workings of these ubiquitous organelles.
脂滴由中性脂质核心组成，周围是带有结合蛋白的磷脂单层。关于脂滴功能的许多信息来自蛋白质组学和脂质组学研究，这些研究确定了从整个系统发育树中的生物体分离出的脂滴成分。在这里，我们通过报告来自裂殖酵母粟酒裂殖酵母的脂滴因子，增加了这一重要的信息库。这项研究的独特之处在于，细胞在三种不同的环境中培养：1）基于葡萄糖的培养基中的对数生长后期阶段，2）基于葡萄糖的培养基中的稳定期，以及3）含有油酸的培养基中的对数生长后期阶段。我们使用活细胞荧光显微镜确认了主要因子与脂滴的共定位。我们还分析了这三种条件下每种条件下的脂滴的甾醇酯（SE）和三酰甘油（TAG）含量，以及它们各自的脂肪酸组成。我们鉴定出一种以前未发现的脂滴蛋白Vip1p，它会影响脂滴大小分布。这些结果为这些普遍存在的细胞器的运作提供了进一步的见解。
