Pederson T
Worcester Foundation for Biomedical Research, Shrewsbury, MA 01545, USA.
J Mol Biol. 1998 Mar 27;277(2):147-59. doi: 10.1006/jmbi.1997.1618.
The possible existence in eukaryotic cells of an internal, non-chromatin nuclear structural framework that facilitates gene readout as a set of spatially concerted reactions has become a popular but controversial theater of investigation. This article endeavors to present a circumspect review of the nuclear matrix concept as we presently know it, framed around two contrasting hypotheses: (1) that an internal nuclear framework actively enhances gene expression (in much the same way the cytoskeleton mediates cell locomotion, mitosis and intracellular vesicular traffic) versus (2) that the interphase chromosomes have fixed, inherited positions and that the DNA replication, transcripton and RNA processing machinery diffusionally arrives at sites of gene readout, with some aspects of nuclear structure thus being more a result than a cause of gene expression. On balance, the available information suggests that interactions among various gene expression machines may contribute to isolated nuclear matrix preparations. Some components of isolated nuclear matrix preparations may also reflect induced or reconfigured protein-protein associations. The protein characterization and ultrastructural analysis of the isolated nuclear matrix has advanced significantly in recent years, although controversies remain. Important new clues are now coming in from promising contemporary lines of research that report on nuclear structure in living cells.
真核细胞中可能存在一种内部的、非染色质的核结构框架，它作为一系列空间协同反应促进基因读出，这已成为一个热门但有争议的研究领域。本文试图围绕两个截然不同的假设，对我们目前所了解的核基质概念进行审慎的综述：（1）一种内部核框架积极增强基因表达（与细胞骨架介导细胞运动、有丝分裂和细胞内囊泡运输的方式非常相似），与（2）间期染色体具有固定的、遗传的位置，并且DNA复制、转录和RNA加工机制通过扩散到达基因读出位点，因此核结构的某些方面更多是基因表达的结果而非原因。总的来说，现有信息表明各种基因表达机器之间的相互作用可能有助于分离的核基质制备。分离的核基质制备的一些成分也可能反映诱导或重新配置的蛋白质-蛋白质关联。尽管仍存在争议，但近年来对分离的核基质的蛋白质表征和超微结构分析有了显著进展。现在，来自有关活细胞中核结构的有前景的当代研究方向的重要新线索不断涌现。
