Geuze H J, Slot J W, Strous G J, Peppard J, von Figura K, Hasilik A, Schwartz A L
Cell. 1984 May;37(1):195-204. doi: 10.1016/0092-8674(84)90315-5.
Using double-label quantitative immunoelectron microscopy on ultrathin cryosections of rat liver, we have compared the endocytotic pathways of the receptors for asialoglycoprotein (ASGP-R), mannose-6-phosphate ligands (MP-R), and polymeric IgA (IgA-R). All three were found within the Golgi complex, along the entire plasma membrane, in coated pits and vesicles, and within a compartment of uncoupling of receptors and ligand ( CURL ). The receptors occurred randomly at the cell surface, in coated pits and vesicles. Within CURL tubules ASGP-R and MP-R were colocalized , but IgA-R and ASGP-R displayed dramatic microheterogeneity. Thus, in addition to its role in uncoupling and sorting recycling receptor from ligand, CURL serves as a compartment to segregate recycling receptor (e.g. ASGP-R) from receptor involved in transcytosis (e.g. IgA-R).
利用对大鼠肝脏超薄冷冻切片进行的双标记定量免疫电子显微镜技术，我们比较了去唾液酸糖蛋白受体（ASGP-R）、甘露糖-6-磷酸配体（MP-R）和聚合免疫球蛋白A（IgA-R）的内吞途径。在整个质膜上、包被小窝和小泡内以及受体与配体解偶联区室（CURL）内的高尔基体复合物中均发现了这三种物质。这些受体随机出现在细胞表面、包被小窝和小泡中。在CURL小管内，ASGP-R和MP-R共定位，但IgA-R和ASGP-R表现出显著的微观异质性。因此，除了在受体与配体解偶联以及将回收受体与配体进行分类方面发挥作用外，CURL还作为一个区室，将回收受体（如ASGP-R）与参与转胞吞作用的受体（如IgA-R）分隔开来。
