Cell and Molecular Biology Department, Centro Investigaciones Biolgicas, Madrid, Spain.
Cell Biol Int. 2012;36(12):1097-105. doi: 10.1042/CBI20120237.
Plant cells have a well organized nucleus and nuclear matrix, but lack orthologues of the main structural components of the metazoan nuclear matrix. Although data is limited, most plant nuclear structural proteins are coiled-coil proteins, such as the NIFs (nuclear intermediate filaments) in Pisum sativum that cross-react with anti-intermediate filament and anti-lamin antibodies, form filaments 6-12 nm in diameter in vitro, and may play the role of lamins. We have investigated the conservation and features of NIFs in a monocot species, Allium cepa, and compared them with onion lamin-like proteins. Polyclonal antisera against the pea 65 kDa NIF were used in 1D and 2D Western blots, ICM (imunofluorescence confocal microscopy) and IEM (immunoelectron microscopy). Their presence in the nuclear matrix was analysed by differential extraction of nuclei, and their association with structural spectrin-like proteins by co-immunoprecipitation and co-localization in ICM. NIF is a conserved structural component of the nucleus and its matrix in monocots with Mr and pI values similar to those of pea 65 kDa NIF, which localized to the nuclear envelope, perichromatin domains and foci, and to the nuclear matrix, interacting directly with structural nuclear spectrin-like proteins. Its similarities with some of the proteins described as onion lamin-like proteins suggest that they are highly related or perhaps the same proteins.
植物细胞具有组织良好的核和核基质，但缺乏后生动物核基质的主要结构成分的同源物。尽管数据有限，但大多数植物核结构蛋白都是卷曲螺旋蛋白，如豌豆中的 NIFs（核中间丝），与抗中间丝和抗核层抗体交叉反应，在体外形成 6-12nm 直径的纤维，可能发挥核层的作用。我们研究了单子叶植物洋葱中的 NIFs 的保守性和特征，并将其与洋葱类核层蛋白进行了比较。针对豌豆 65kDa NIF 的多克隆抗血清用于 1D 和 2D Western blot、ICM（免疫荧光共聚焦显微镜）和 IEM（免疫电子显微镜）。通过核的差异提取分析它们在核基质中的存在，通过共免疫沉淀和 ICM 中的共定位分析它们与结构类似血影蛋白的蛋白的关联。NIF 是单子叶植物核和核基质的保守结构成分，其 Mr 和 pI 值与豌豆 65kDa NIF 相似，定位于核膜、染色质周围区域和焦点以及核基质，与结构核类似血影蛋白的蛋白直接相互作用。它与一些被描述为洋葱类核层蛋白的蛋白的相似性表明它们是高度相关的，或者可能是相同的蛋白。
