Cell biology - How cells handle cholesterol

Cholesterol plays an indispensable role in regulating the properties of cel l membranes in mammalian cells. Recent advances suggest that cholesterol ex erts many of its actions mainly by maintaining sphingolipid rafts in a func tional state. How rafts contribute to cholesterol metabolism and transport in the cell is still an open issue. It has Long been known that cellular ch olesterol Levels are precisely controlled by biosynthesis, efflux from cell s, and influx of Lipoprotein cholesterol into cells. The regulation of chol esterol homeostasis is now receiving a new focus, and this changed perspect ive may throw Light on diseases caused by cholesterol excess, the prime exa mple being atherosclerosis.