MULTITUDE OF INVERTED REPEATS CHARACTERIZES A CLASS OF ANCHORAGE SITES OF CHROMATIN LOOPS TO THE NUCLEAR MATRIX
MULTITUDE OF INVERTED REPEATS CHARACTERIZES A CLASS OF ANCHORAGE SITES OF CHROMATIN LOOPS TO THE NUCLEAR MATRIX
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DOI：
10.1002/jcb.240530102
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发表时间：
1993-09-01
影响因子：
4
通讯作者：
KONG, CF
中科院分区：
文献类型：
--
作者：
BOULIKAS, T;KONG, CF
为了了解DNA序列的性质，组织染色质成域或环，我们已经克隆了核基质DNA（总DNA的1.7%），从培养的人髓性白血病细胞。核基质是由约0.1至5.0 kb的特定DNA片段与蛋白质转录因子、核酶和结构蛋白相互作用形成的。核基质被认为是DNA复制、转录和修复起始的唯一核微环境。DNA的基质附着区（MARs）具有转录增强子活性，是人类基因组复制的起点，并限定相邻染色质环之间的边界。在这项研究中，我们报告的人MAR片段19.2的大小为542 bp的序列。Hum. MAR 19.2由TG-、CA-、CT-和GA-富集区组成，并显示8个完全和不完全反向重复序列。因此，我们已经确定了一类新的MAR的序列特征不同的AT-丰富的类MAR。19.2序列的反向重复序列可能通过扭转应变和特定的转录/复制蛋白因子稳定为它们的十字形构型。该MAR可能在侧翼染色单体结构域的复制起始中起作用，并且在该结构域中存在的基因的转录活性的调节中起作用。 (C)1993 Wiley-Liss，Inc.
In order to understand the nature of DNA sequences that organize chromatin into domains or loops, we have cloned the nuclear matrix DNA (1.7% of the total DNA) from human myelogeneous leukemia cells in culture. Nuclear matrix is formed by interactions between specific stretches of DNA of about 0.1 to 5.0 kb with protein transcription factors, nuclear enzymes, and structural proteins. Nuclear matrix is believed to be the exclusive nuclear microenvironment in which initiation of DNA replication, transcription, and repair take place. The matrix attachment regions (MARs) of DNA have transcriptional enhancer activity, harbor the origins of replication of the human genome and define the borders between.neighboring chromatin loops. In this study we report the sequence of the human MAR fragment 19.2 of a size of 542 bp. Hum. MAR 19.2 is composed of TG-, CA-, CT-, and GA-rich blocks and shows 8 perfect and imperfect inverted repeats. Thus, we have identified a novel class of MARs with sequence characteristics divergent from the AT-rich class of MARs. The inverted repeats of the 19.2 sequence might be stabilized into their cruciform configuration by torsional strain and by specific transcription/replication protein factors. This MAR might function in the initiation of replication of the flanking chromatim domain and in the regulation of the transcriptional activity of the gene(s) that reside in this domain. (C) 1993 Wiley-Liss, Inc.