Davie J R, Hendzel M J
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
J Cell Biochem. 1994 May;55(1):98-105. doi: 10.1002/jcb.240550112.
Besides its role in organizing nuclear DNA, the nuclear matrix is involved in specific nuclear functions, including replication, transcription, and RNA splicing. It is becoming increasingly evident that nuclear processes are localized to distinct regions in the nucleus. For example, transcriptionally active genes and RNA transcripts are found in discrete transcription foci. Current evidence suggests that nuclear matrix-bound transcriptionally active DNA sequences are in nucleosomes with dynamically acetylated histones. Histone acetylation, which precedes transcription, alters nucleosome and chromatin structure, decondensing the chromatin fibre and making the nucleosomal DNA accessible to transcription factors. Histone acetyltransferase and histone deacetylase, which catalyze this rapid acetylation and deacetylation, are associated with the internal nuclear matrix. We hypothesize that these enzymes play a role in maintaining the association of the active chromatin domains with the internal nuclear matrix at sites of ongoing transcription.
除了在组织核DNA方面发挥作用外，核基质还参与特定的核功能，包括复制、转录和RNA剪接。越来越明显的是，核过程定位于细胞核内的不同区域。例如，转录活性基因和RNA转录本存在于离散的转录灶中。目前的证据表明，与核基质结合的转录活性DNA序列存在于具有动态乙酰化组蛋白的核小体中。转录之前发生的组蛋白乙酰化会改变核小体和染色质结构，使染色质纤维解聚，并使核小体DNA能够被转录因子识别。催化这种快速乙酰化和去乙酰化的组蛋白乙酰转移酶和组蛋白脱乙酰酶与内核基质相关联。我们假设这些酶在正在进行转录的位点维持活性染色质结构域与内核基质的关联中发挥作用。
