Nickerson J A, Penman S
Dept. Biology, Massachusetts Institute of Technology, Cambridge 02139.
Cell Biol Int Rep. 1992 Aug;16(8):811-26. doi: 10.1016/s0309-1651(05)80024-4.
The gentle removal of chromatin uncovers a nuclear matrix consisting of two parts: a nuclear lamina connected to the intermediate filaments of the cytoskeleton and an internal matrix of thick, polymorphic fibers connecting the lamina to masses in the nuclear interior. This internal nuclear matrix can be further fractionated to uncover a highly branched network of 9 nm and 13 nm core filaments retaining some enmeshed bodies. The core filament network retains most of the nuclear RNA, as well as the fA12RNP antigen, and may be the most basic or core element of internal nuclear structure. One high molecular weight protein component of the core filament network, the H1B2 antigen, is normally masked in the interphase nucleus and is uncovered as the chromatin condenses at mitosis. This protein is associated with a fibrogranular network surrounding and connected to the chromosomes. The core filament-associated fA12 antigen also becomes associated with this perichromosomal network. We propose that the core filament nuclear matrix structure may not completely disassemble at mitosis but, rather, that parts remain as a structural network connected to chromosomes and other mitotic structures. These mitotic networks may, in turn, serve as the core structures on which the nuclear matrices of daughter cells are built.
轻柔地去除染色质后，会暴露出一个由两部分组成的核基质：一部分是与细胞骨架中间丝相连的核纤层，另一部分是由粗大的多形纤维构成的内部基质，这些纤维将核纤层与核内的团块相连。这种核内基质可以进一步分级分离，以揭示一个由9纳米和13纳米的核心细丝组成的高度分支网络，其中还保留着一些缠结体。核心细丝网络保留了大部分核RNA以及fA12RNP抗原，可能是核内结构最基本或核心的元素。核心细丝网络的一种高分子量蛋白质成分，即H1B2抗原，在间期核中通常被掩盖，在有丝分裂时随着染色质浓缩而暴露出来。这种蛋白质与围绕并连接染色体的纤维颗粒网络相关联。与核心细丝相关的fA12抗原也与这个染色体周围网络相关联。我们提出，核心细丝核基质结构在有丝分裂时可能不会完全解体，而是部分保留为与染色体和其他有丝分裂结构相连的结构网络。这些有丝分裂网络反过来可能作为构建子细胞核基质的核心结构。
