Nickerson J A, Blencowe B J, Penman S
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
Int Rev Cytol. 1995;162A:67-123. doi: 10.1016/s0074-7696(08)61229-2.
Nucleic acid metabolism is structurally organized in the nucleus. DNA replication and transcription have been localized to particular nuclear domains. Additional domains have been identified by their morphology or by their composition; for example, by their high concentration of factors involved in RNA splicing. The domain organization of the nucleus is maintained by the nuclear matrix, a nonchromatin nuclear scaffolding that holds most nuclear RNA and organizes chromatin into loops. The nuclear matrix is built on a network of highly branched core filaments that have an average diameter of 10 nm. Many of the intermediates and the regulatory and catalytic factors of nucleic acid metabolism are retained in nuclear matrix preparations, suggesting that nucleic acid synthesis and processing are structure-bound processes in cells. Tissue-specific and malignancy-induced variations in nuclear structure and metabolism may result from altered matrix architecture and composition.
核酸代谢在细胞核中进行结构组织。DNA复制和转录已定位到特定的核区域。其他区域则通过其形态或组成来识别，例如，通过其高浓度参与RNA剪接的因子来识别。细胞核的区域组织由核基质维持，核基质是一种非染色质的核支架，它容纳了大多数核RNA，并将染色质组织成环。核基质建立在高度分支的核心细丝网络上，这些细丝的平均直径为10纳米。核酸代谢的许多中间产物以及调节和催化因子都保留在核基质制剂中，这表明核酸合成和加工是细胞中的结构结合过程。核结构和代谢的组织特异性及恶性肿瘤诱导的变化可能源于基质结构和组成的改变。
