Brefeldin A affects the cellular distribution of endocytic receptors differentially.

The cell surface expression of three endocytic receptors was studied in human hepatoma Hep G2 cells treated with brefeldin A (BFA). Ligand binding and cell surface iodination revealed that BFA increased the number of mannose 6-phosphate/insulin-like growth factor II receptors twofold and decreased the amount of asialoglycoprotein and transferrin receptors by 40-60%. The altered expression of receptors at the cell surface was paralleled by changes in the respective ligand uptake. The implications of this finding on our understanding of intracellular trafficking are discussed.