Paulin-Levasseur M, Blake D L, Julien M, Rouleau L
Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada K1N 6N5.
Chromosoma. 1996;104(5):367-79. doi: 10.1007/BF00337226.
The characterization of the human antiserum designated MAN has led to the identification of a subset of non-lamin proteins that are exclusively located at the nuclear periphery in all vertebrate cell types examined, from human to fish. Immunoreactive protein species were shown to comprise three major polypeptides of Mr 78000, 58000 and 40000. These antigens co-partitioned with the nuclear lamina during in situ isolation of nuclear matrices from lamin A/C-positive and -negative mammalian cells. Using double immunofluorescence, the spatial relationship of MAN antigens to type-A and type-B lamins was further examined throughout the cell cycle of lamin A/C-positive mammalian cells. In interphase HeLa and 3T3 cells, MAN antigens colocalized with both types of lamins at the periphery of the nucleus, but were absent from intranuclear foci of lamin B. As HeLa cells proceeded into mitosis, MAN antigens were seen to segregate from lamins A/C and coredistribute with lamin B. Lamins A/C disassembled during late prophase/early prometaphase and reassociated with chromatin in telophase/cytokinesis. In contrast, MAN antigens and lamin B dispersed late during prometaphase and reassembled on chromosomes in anaphase. Altogether, our data suggest that MAN antigens may play key functions in the maintenance of the structural integrity of the nuclear compartment in vertebrate cells.
对名为MAN的人抗血清的特性分析，已鉴定出一类非核纤层蛋白亚群，在从人类到鱼类的所有被检测脊椎动物细胞类型中，它们专门定位于核周边。免疫反应性蛋白种类显示由分子量为78000、58000和40000的三种主要多肽组成。在从A/C型核纤层蛋白阳性和阴性的哺乳动物细胞原位分离核基质的过程中，这些抗原与核纤层共同分离。利用双重免疫荧光，在A/C型核纤层蛋白阳性的哺乳动物细胞的整个细胞周期中，进一步检测了MAN抗原与A型和B型核纤层蛋白的空间关系。在间期的HeLa细胞和3T3细胞中，MAN抗原在核周边与两种类型的核纤层蛋白共定位，但在核纤层蛋白B的核内聚集区不存在。随着HeLa细胞进入有丝分裂，可见MAN抗原与A/C型核纤层蛋白分离，并与核纤层蛋白B共分布。A/C型核纤层蛋白在前期晚期/早中期解体，并在末期/胞质分裂期与染色质重新结合。相比之下，MAN抗原和核纤层蛋白B在中期晚期分散，并在后期重新组装在染色体上。总之，我们的数据表明，MAN抗原可能在维持脊椎动物细胞核区室结构完整性方面发挥关键作用。
