Kaplan M R, Simoni R D
J Cell Biol. 1985 Aug;101(2):446-53. doi: 10.1083/jcb.101.2.446.
We have studied the transport of newly synthesized cholesterol from the endoplasmic reticulum to the plasma membrane in Chinese hamster ovary cells using a cell fractionation assay. We found that transport is dependent on metabolic energy, but that the maintenance of the high differential concentration of cholesterol in the plasma membrane is not an energy-requiring process. We have tested a variety of inhibitors for their effect on cholesterol transport and found that cytochalasin B, colchicine, monensin, cycloheximide, and NH4Cl did not have any effect. The cholesterol transport process shows a sharp temperature dependence; it ceases at 15 degrees C, whereas cholesterol synthesis continues. When synthesis occurs at 15 degrees C, the newly synthesized cholesterol accumulates in the endoplasmic reticulum and in a low density, lipid-rich vesicle fraction. These results suggest that cholesterol is transported via a vesicular system.
我们利用细胞分级分离测定法，研究了中国仓鼠卵巢细胞中，新合成的胆固醇从内质网到质膜的转运过程。我们发现，转运过程依赖于代谢能量，但质膜中胆固醇高差异浓度的维持并非能量需求过程。我们测试了多种抑制剂对胆固醇转运的影响，发现细胞松弛素B、秋水仙碱、莫能菌素、环己酰亚胺和氯化铵均无任何作用。胆固醇转运过程表现出明显的温度依赖性；在15摄氏度时停止，而胆固醇合成仍在继续。当在15摄氏度进行合成时，新合成的胆固醇在内质网和低密度、富含脂质的囊泡部分中积累。这些结果表明，胆固醇是通过囊泡系统进行转运的。
