Staufenbiel M, Deppert W
Eur J Cell Biol. 1983 Sep;31(2):341-8.
The major polypeptides of nuclear matrix preparations from vertebrate tissues are rather similar. However, nuclear matrix fractions isolated from cultured vertebrate cells of different origin show variations in their major polypeptides. We demonstrate that cytoplasmic intermediate filaments copurify with nuclear matrices from these cells. Because of their abundance, their subunit proteins form major bands on SDS-polyacrylamide gels. The tissue specificity of the intermediate filament proteins then gives rise to the variations observed. To explain the differences in major proteins of nuclear matrices isolated from vertebrate cells grown in tissue and in culture we have analyzed the distribution of intermediate filaments during isolation of nuclei from liver tissue. We show that during homogenization of liver intermediate filaments are torn off and can be separated from the nuclei. Nuclear matrix preparations from these nuclei, therefore, do not contain intermediate filaments and true nuclear matrix proteins (e.g. lamins) are the major protein species. Our results suggest that the major nuclear matrix polypeptides (lamins) are similar in all vertebrate cells, since lamin like proteins were identified in cultured cells, too. Using antisera we demonstrate an immunological difference between lamins A/C and lamin B.
脊椎动物组织中核基质制剂的主要多肽颇为相似。然而，从不同来源的培养脊椎动物细胞中分离得到的核基质组分，其主要多肽存在差异。我们证明，细胞质中间丝与这些细胞的核基质共同纯化。由于它们数量众多，其亚基蛋白在十二烷基硫酸钠-聚丙烯酰胺凝胶上形成主要条带。中间丝蛋白的组织特异性进而导致了所观察到的差异。为了解释从组织和培养中生长的脊椎动物细胞分离得到的核基质主要蛋白质的差异，我们分析了从肝脏组织分离细胞核过程中中间丝的分布。我们表明，在肝脏匀浆过程中，中间丝会被扯断并可与细胞核分离。因此，来自这些细胞核的核基质制剂不含中间丝，真正的核基质蛋白（如核纤层蛋白）是主要的蛋白质种类。我们的结果表明，所有脊椎动物细胞中的主要核基质多肽（核纤层蛋白）相似，因为在培养细胞中也鉴定出了类似核纤层蛋白的蛋白质。使用抗血清，我们证明了核纤层蛋白A/C和核纤层蛋白B之间存在免疫差异。
