Lipid dropletsLipid dropletsLipid droplets are specialized organelles for the cellular storage and metabolism of neutral lipids, primarily in the form of triacylglycerols and sterol esters. Droplets are of various sizes and have a unique structure consisting of a hydrophobic core, containing the lipids, and a surrounding phospholipid monolayer, or hemimembrane, which contains various integral and peripheral membrane proteins. These proteins include enzymes involved in lipid droplet formation, lipid metabolism and metabolic signaling, but also include histones and ribosomes. Lipid droplets enable dynamic storage of lipids used for energy metabolism, biosynthesis of cellular membranes and lipid signaling pathways, but also sequesters toxic lipids and stores membrane proteins. Immunofluorescent stainingLipid droplets are vesicle-like structures that can vary in size and number. Staining of proteins in larger lipid droplets usually give a characteristic ring-like appearance due to their localization to the outer phospholipid layer and absence from the hydrophobic core. However, given the fact that lipid droplets can be difficult to distinguish from different vesicles and other membranous structures, co-localization with hydrophobic marker dyes or marker proteins is usually required to confirm a localization to lipid droplets. Read more about the proteome of lipid droplets as a substructure of vesicles. PLIN3Perilipin 3 (PLIN3) is a member of a family of lipid droplet coating proteins that are involved in the regulation of lipid metabolism. Perilipins serve as gate keepers by regulating access to the lipid droplet core for proteins involved in lipid synthesis as well as lipolysis. Their expression varies in a combinatorial manner between cell types and in response to metabolic needs of the cell. |