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Decreasing Phosphatidylcholine on the Surface of the Lipid Droplet Alters Protein Binding
Author(s) -
Townsend Elizabeth,
Hains Anastasia,
Brown Elizabeth,
Rickertsen Cassandra,
Kharbanda Kusum,
Listenberger Laura
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.715.31
Subject(s) - perilipin , lipid droplet , phospholipid , phosphatidylcholine , phosphatidylethanolamine , chemistry , intracellular , organelle , biochemistry , biophysics , microbiology and biotechnology , biology , lipolysis , membrane , adipose tissue
Excess lipid is stored in an intracellular organelle known as the lipid droplet. While the core of the lipid droplet is rich in neutral lipids, the surface is primarily comprised of two phospholipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE). The lipid droplet surface is further decorated with proteins, such as perilipin 2, which facilitate lipid storage and utilization. Here, we show that changes to the phospholipid composition of the lipid droplet surface alters protein binding to the lipid droplet. We utilize studies with synthetic lipid droplets to demonstrate that reduced ratios of PC:PE increase the binding of perilipin 2 in vitro . Moreover, altering the availability of intracellular PC by growing NIH 3T3 cells in choline deficient media decreases the PC:PE ratio on lipid droplets and increases intracellular perilipin 2 association with the lipid droplet. While total levels of lipid droplet‐associated proteins are not changed, choline deficiency alters the ability of other unidentified proteins to associate with the lipid droplet. Future experiments will seek to identify these currently unknown proteins, and continue to explore the connections between the lipid droplet phospholipid composition, protein binding, and the ability of the lipid droplet to store and utilize fat.