Senior A, Gerace L
Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
J Cell Biol. 1988 Dec;107(6 Pt 1):2029-36. doi: 10.1083/jcb.107.6.2029.
We obtained a monoclonal antibody (RL13) that identifies three integral membrane proteins specific to the nuclear envelope of rat liver, a major 75-kD polypeptide and two more minor components of 68 and 55 kD. Immunogold labeling of isolated nuclear envelopes demonstrates that these antigens are localized specifically to the inner nuclear membrane, and that the RL13 epitope occurs on the inner membrane's nucleoplasmic surface where the nuclear lamina is found. When nuclear envelopes are extracted with solutions containing nonionic detergent and high salt to solubilize nuclear membranes and pore complexes, most of these integral proteins remain associated with the insoluble lamina. Since the polypeptides recognized by RL13 are relatively abundant, they may function as lamina attachment sites in the inner nuclear membrane. Major cross-reacting antigens are found by immunoblotting and immunofluorescence microscopy in all rat cells examined. Therefore, these integral proteins are biochemical markers for the inner nuclear membrane and will be useful models for studying nuclear membrane biogenesis.
我们获得了一种单克隆抗体（RL13），它能识别三种大鼠肝脏核膜特有的整合膜蛋白，一种主要的75kD多肽以及另外两种分子量较小的68kD和55kD的组分。对分离出的核膜进行免疫金标记显示，这些抗原特异性定位于内核膜，并且RL13表位出现在内核膜的核质表面，即核纤层所在的位置。当用含有非离子去污剂和高盐的溶液提取核膜以溶解核膜和核孔复合体时，这些整合蛋白中的大多数仍与不溶性核纤层相关联。由于RL13识别的多肽相对丰富，它们可能在内核膜中作为核纤层附着位点发挥作用。通过免疫印迹和免疫荧光显微镜检查，在所有检测的大鼠细胞中均发现了主要的交叉反应抗原。因此，这些整合蛋白是内核膜的生化标志物，将成为研究核膜生物发生的有用模型。
