Aebi U, Cohn J, Buhle L, Gerace L
Nature. 1986;323(6088):560-4. doi: 10.1038/323560a0.
The nuclear lamina, a protein meshwork lining the nucleoplasmic surface of the inner nuclear membrane, is thought to provide a framework for organizing nuclear envelope structure and an anchoring site at the nuclear periphery for interphase chromatin. In several higher eukaryotic cells, the lamina appears to be a polymer comprised mainly of one to three immunologically related polypeptides of relative molecular mass (Mr) 60,000-75,000 (60-70K) termed lamins. Three lamins (A, B, and C) are typically present in mammalian somatic cells. Previous studies on nuclear envelopes of rat liver and Xenopus oocytes suggested that the lamina has a fibrillar or filamentous substructure. Interestingly, protein sequences recently deduced for human lamins A and C from complementary DNA clones indicate that both of these polypeptides contain a region of approximately 350 amino acids very similar in sequence to the coiled-coil alpha-helical rod domain that characterizes all intermediate-type filament (IF) proteins. Here we analyse the supramolecular organization of the native nuclear lamina and the structure and assembly properties of purified lamins, and show that the lamins constitute a previously unrecognized class of IF polypeptides.
核纤层是一种位于内核膜核质表面的蛋白质网络，被认为可为核膜结构的组织提供框架，并为间期染色质提供核周锚定位点。在几种高等真核细胞中，核纤层似乎是一种聚合物，主要由一到三种相对分子质量（Mr）为60,000 - 75,000（60 - 70K）的免疫相关多肽组成，这些多肽被称为核纤层蛋白。哺乳动物体细胞中通常存在三种核纤层蛋白（A、B和C）。先前对大鼠肝脏和非洲爪蟾卵母细胞核膜的研究表明，核纤层具有纤维状或丝状亚结构。有趣的是，最近从互补DNA克隆中推导出来的人类核纤层蛋白A和C的蛋白质序列表明，这两种多肽都包含一个约350个氨基酸的区域，其序列与所有中间丝（IF）蛋白特有的卷曲螺旋α - 螺旋杆结构域非常相似。在这里，我们分析了天然核纤层的超分子组织以及纯化核纤层蛋白的结构和组装特性，并表明核纤层蛋白构成了一类以前未被认识的中间丝多肽。
