Abstract
The diversity of fatty acids in biomembranes is extensive enough to alter membrane fluidity and may affect both the localization of membrane proteins and the cellular functions. In this study, we examined the regulation of biomembrane fatty acids according to nutritional status in terms of fatty acid deficiency or excess. In mammals, Mead acid (C20:3n-9) is synthesized from oleic acid when essential fatty acids are deficient. Using siRNA-mediated knockdown of fatty acid desaturases and elongases, we revealed the genes and pathways involved in Mead acid synthesis in cultured cells, and in another study we examined the fatty acid compositions of phospholipids in the lipid droplet (LD) monolayer during differentiation of 3T3-L1 adipocytes. The levels of saturated fatty acids in the LD monolayer decreased, whereas the levels of unsaturated fatty increased, during differentiation. These results suggest that the phospholipid monolayer in mature LDs is more fluid than that in nascent LDs. These data provide evidence that the biophysical properties of the phospholipid monolayer in LDs change during adipocyte differentiation.
