Ciska Malgorzata, Masuda Kiyoshi, Moreno Díaz de la Espina Susana
Cell and Molecular Biology Department, Centre of Biological Research, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
Laboratory of Crop Physiology, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan.
Chromosoma. 2018 Mar;127(1):103-113. doi: 10.1007/s00412-017-0649-2. Epub 2017 Oct 27.
Nuclear lamina organization is similar in metazoan and plants though the latter lack orthologs of lamins, the main components of the metazoan lamina. Current evidence suggests that Nuclear Matrix Constituent Proteins (NMCPs) are the lamin analogues in plants as these proteins share several key features: higher-order secondary structure and domain layout, subnuclear distribution, and involvement in the regulation of nuclear shape and size, as well as in higher-order chromatin organization. Previously, we studied the NMCP family in flowering plants (angiosperms), in which it comprises two phylogenetic groups: NMCP1 and NMCP2. At present, in silico information about NMCP proteins in embryophytes is relatively advanced, though very few proteins, most of them of the NMCP1 type, have been extensively studied in vivo. We previously characterized the NCMP1 protein in the monocot Allium cepa. Here, we report the key features of a second protein of this species NMCP2, which presents a conserved sequence and domain layout. Immunofluorescence and immunoelectronmicroscopy evidence co-localization of endogenous AcNMCP2 and AcNMCP1 in the lamina, while Western blotting and immunoconfocal microscopy reveal a similar pattern of expression and distribution of both NMCP proteins in different root tissues. Our results provide novel insight about endogenous NMCP2-type proteins and complete the characterization of the NMCP family in A. cepa, thus advancing the current understanding of these structural proteins constituting the plant lamina.
后生动物和植物的核纤层组织相似，尽管植物缺乏核纤层蛋白的直系同源物，而核纤层蛋白是后生动物核纤层的主要成分。目前的证据表明，核基质组成蛋白（NMCPs）是植物中的核纤层类似物，因为这些蛋白具有几个关键特征：高阶二级结构和结构域布局、亚核分布，以及参与核形状和大小的调节，以及高阶染色质组织。此前，我们研究了开花植物（被子植物）中的NMCP家族，该家族包括两个系统发育组：NMCP1和NMCP2。目前，关于胚植物中NMCP蛋白的计算机信息相对先进，尽管很少有蛋白，其中大多数是NMCP1类型，已在体内进行了广泛研究。我们之前对单子叶植物洋葱中的NCMP1蛋白进行了表征。在这里，我们报告了该物种第二种蛋白NMCP2的关键特征，它呈现出保守的序列和结构域布局。免疫荧光和免疫电子显微镜证据表明内源性AcNMCP2和AcNMCP1在核纤层中共定位，而蛋白质印迹法和免疫共聚焦显微镜揭示了两种NMCP蛋白在不同根组织中的表达和分布模式相似。我们的结果为内源性NMCP2型蛋白提供了新的见解，并完成了洋葱中NMCP家族的表征，从而推进了目前对构成植物核纤层的这些结构蛋白的理解。
