Shapiro J, Sciaky N, Lee J, Bosshart H, Angeletti R H, Bonifacino J S
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
J Histochem Cytochem. 1997 Jan;45(1):3-12. doi: 10.1177/002215549704500102.
Furin is a dibasic endopeptidase responsible for the proteolytic maturation of many precursor proteins in the secretory and endocytic pathways of mammalian cells. The levels of furin expression in most cells are very low, and this has hampered attempts to identify the intracellular compartments in which endogenous furin is localized. We have used a specific antibody reagent to a sequence in the carboxy terminus of furin to perform immunofluorescent staining of mammalian cell lines. This antibody was sensitive enough to detect staining for furin in various cell lines. For the most part, furin staining was confined to a juxtanuclear structure characteristic of the Golgi complex. Analyses by video microscopy and confocal microscopy showed that the distribution of furin was distinct from that of mannosidase II, a marker of the Golgi stack, and most closely resembled that of TGN38, a marker of the trans-Golgi network. Therefore, our results suggest that endogenous furin is predominantly localized to the area of the Golgi complex, most likely within the trans-Golgi network.
弗林蛋白酶是一种双碱性内肽酶，负责哺乳动物细胞分泌和内吞途径中许多前体蛋白的蛋白水解成熟。大多数细胞中弗林蛋白酶的表达水平非常低，这阻碍了人们识别内源性弗林蛋白酶所在细胞内区室的尝试。我们使用了一种针对弗林蛋白酶羧基末端序列的特异性抗体试剂，对哺乳动物细胞系进行免疫荧光染色。该抗体灵敏度足以检测各种细胞系中弗林蛋白酶的染色情况。在大多数情况下，弗林蛋白酶染色局限于高尔基体复合体特有的近核结构。通过视频显微镜和共聚焦显微镜分析表明，弗林蛋白酶的分布与高尔基体堆栈标志物甘露糖苷酶II不同，与反式高尔基体网络标志物TGN38最为相似。因此，我们的结果表明内源性弗林蛋白酶主要定位于高尔基体复合体区域，很可能位于反式高尔基体网络内。
