Fig. 7.

Model for CD-mediated cholesterol trafficking. CD promotes the redistribution of the lysosomal cholesterol pool. A: In the presence of lipoproteins, lysosomal cholesterol is trafficked to the PM, where CD promotes exchange with serum lipoproteins (acceptors). Lysosomal cholesterol is also trafficked to the ER, directly or indirectly by way of the PM, and is reesterified. B: In the absence of suitable acceptors in the media, lysosomal cholesterol is not effluxed but rather accumulates in the PM. Arrival of the cholesterol at the ER and reesterification are enhanced under lipoprotein-deficient conditions.