Levy-Wilson B
Gladstone Foundation Laboratories for Cardiovascular Disease, Department of Pharmaceutical Chemistry, University of California, San Francisco 94140-0608.
Biochem Biophys Res Commun. 1990 Aug 31;171(1):162-8. doi: 10.1016/0006-291x(90)91371-x.
The chromatin structure of the 3' end of the human apolipoprotein B gene has been examined. Two DNaseI hypersensitive sites were present in nuclei from liver-derived HepG2 cells and intestine-derived CaCo-2 cells, in which the apo-B gene is transcriptionally active, but were absent from HeLa cells, where the gene is not expressed, and from free DNA. The region in a segment enriched in recognition sites for topoisomerase II and known to participate in anchoring the 3' end of the gene to the nuclear matrix. The second DNaseI hypersensitive site resided in the 3' untranslated portion of the gene. Furthermore, nucleosomes were present along a 1.4-kilobase (HindIII-BamHI) segment of DNA containing the two 3' DNaseI hypersensitive sites, and a static array of nucleosomes was present along the A/T-rich hypervariable region.
已对人载脂蛋白B基因3'端的染色质结构进行了研究。在源自肝脏的HepG2细胞和源自肠道的CaCo-2细胞的细胞核中存在两个DNaseI超敏位点，载脂蛋白B基因在这些细胞中具有转录活性，但在该基因不表达的HeLa细胞以及游离DNA中不存在。该区域位于一段富含拓扑异构酶II识别位点的片段中，已知该片段参与将基因的3'端锚定到核基质。第二个DNaseI超敏位点位于基因的3'非翻译部分。此外，沿着包含两个3' DNaseI超敏位点的1.4千碱基（HindIII - BamHI）DNA片段存在核小体，并且沿着富含A/T的高变区存在静态排列的核小体。
