title: Morphologically and Functionally Distinct Lipid Droplet Subpopulations.
abstract: Lipid droplet (LD), a multi-functional organelle, is often found to associate with other cellular membranous structures and vary in size in a given cell, which may be related to their functional diversity. Here we established a method to separate LD subpopulations from isolated CHO K2 LDs into three different size categories. The subpopulation with smallest LDs was nearly free of ER and other membranous structures while those with larger LDs contained intact ER. These distinct subpopulations of LDs differed in their protein composition and ability to recruit proteins. This method was also applicable to LDs obtained from other sources, such as Huh7 cells, mouse liver and brown adipose tissue, et al. We developed an in vitro assay requiring only isolated LDs, Coenzyme A, and ATP to drive lipid synthesis. The LD subpopulation nearly depleted of ER was able to incorporate fatty acids into triacylglycerol and phospholipids. Together, our data demonstrate that LDs in a given cell are heterogeneous in size and function, and suggest that LDs are one of cellular lipid synthetic organelles.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Shuyan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.|School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Liujuan
authors.initials: L
authors.lastname: Cui
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Deng
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Shimeng
authors.initials: S
authors.lastname: Xu
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jinhai
authors.initials: J
authors.lastname: Yu
authors.affiliation: School of Life Sciences, La Trobe University, Melbourne Victoria 3086, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Cichello
authors.affiliation: A&G Pharmaceutical, Inc., Columbia, Maryland 21045, USA.
authors.forename: Ginette
authors.initials: G
authors.lastname: Serrero
authors.affiliation: University of Texas Southwestern Medical Center, Dallas 75390, USA.
authors.forename: Yunshu
authors.initials: Y
authors.lastname: Ying
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Pingsheng
authors.initials: P
authors.lastname: Liu