Interactomic study on interaction between lipid droplets and mitochondria

Abstract

An increasing body of evidence shows that the lipid droplet, a neutral lipid storage organelle, plays a role in lipid metabolism and energy homeostasis through its interaction with mitochondria. However, the cellular functions and molecular mechanisms of the interaction remain ambiguous. Here we present data from transmission electron microscopy, fluorescence imaging, and reconstitution assays, demonstrating that lipid droplets physically contact mitochondria in vivo and in vitro. Using a bimolecular fluorescence complementation assay in Saccharomyces cerevisiae, we generated an interactomic map of protein-protein contacts of lipid droplets with mitochondria and peroxisomes. The lipid droplet proteins Erg6 and Pet10 were found to be involved in 75% of the interactions detected. Interestingly, interactions between 3 pairs of lipid metabolic enzymes were detected. Collectively, these data demonstrate that lipid droplets make physical contacts with mitochondria and peroxisomes, and reveal specific molecular interactions that suggest active participation of lipid droplets in lipid metabolism in yeast.

Proteomic Study and Marker Protein Identification of Caenorhabditis elegans Lipid Droplets

“…It has been proposed that mitochondria, peroxisomes, ER membranes, and endosomes may be physically associated with LDs (5,34) or may even be continuous with LDs in terms of phospholipid membrane topology (35). Recently, we conducted an interactomic study on interaction between LDs and mitochondria and identified several pairs of proteins that may be involved in this interaction (36).…”

The size matters: regulation of lipid storage by lipid droplet dynamics

“…Dysregulated LD homeostasis is closely connected to many pathological conditions and the development of various diseases reactive oxygen species (ROS). peroxisome, organelles responsible for lipid oxidation, also have close association with LDs, and Plin5 has been identified to mediate the interaction between LD and mitochondria and may facilitate the transport of FA for oxidative phosphorylation with increased energy demand (Gao and Goodman, 2015;Lodhi and Semenkovich, 2014;Mason and Watt, 2015;Pu et al, 2011;Rambold et al, 2015;Schrader, 2001;Yu et al, 2015). LDs are also observed surrounding the nucleus or actually present in the nucleus that may function to store specific proteins or sequester transcriptional factors Welte, 2015).…”

The proteomics of lipid droplets: structure, dynamics, and functions of the organelle conserved from bacteria to humans

“…ERG6 was shown to be a sterol ⌬ 24 -methy ltransferas ( 97 ) and to mediate the interaction between lipid droplets and mitochondria ( 98 ). Proteomic studies of lipid droplets from another yeast strain, Yarrowia lipolytica , also identifi ed lipid synthetic enzymes and membrane-traffi cking proteins ( 37 ).…”