Feeding-fasting dependent recruitment of membrane microdomain proteins to lipid droplets purified from the liver.

摘要: Lipid droplets (LDs) are cellular stores of neutral fat that facilitate lipid and protein trafficking in response to metabolic cues. Unlike other vesicles, the phospholipid membrane on LD is a monolayer. Interestingly, this monolayer has free cholesterol, may therefore contain microdomains serve as platform for assembling proteins involved signal transduction, cell polarity, pathogen entry etc. In support this, culture studies have detected microdomain-associated "raftophilic" LDs. However, physiological significance observation been unclear. Here we show two (Flotillin-1 SNAP23) bind associate differently with LDs purified from rat liver depending feeding/fasting state animal. Flotillin-1 increases fed state, possibly because interact endoplasmic reticulum (ER), facilitating supply flotillin-1 ER increase correlated an cholesterol state. opposite behaviour flotillin-1, SNAP23 fasted appears mediate LD-mitochondria interactions. Such interactions provide fatty acids mitochondria promoting beta-oxidation hepatocytes fasting. Our work brings out physiologically relevant aspects droplet biology different from, not be entirely possible replicate study culture.