Lao Wei-De, Zhang Chuan-Sheng, Hu Guo-Fa, Zhang Xu-Chen, Wei Ying-Yun
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100080, China.
Yi Chuan Xue Bao. 2003 May;30(5):397-406.
Chromosomal DNA in higher eukaryotes is spatially organized into loops by periodic attachment to the nuclear matrix at its base via a specific matrix attachment region (MAR). In order to study the nature of DNA sequences that affixed the loops to the nuclear matrix, we have cloned the MAR DNA from bovine lactating mammary tissues. In vitro binding assay showed that the cloned fragments could be co-complexed with nuclear matrix proteins to form insoluble complex easily removed by centrifugation. Sequences of the two chosen MAR loci are composed of TG-, CA- and GA- blocks, as well as the ATTA motifs. Both the MAR loci show numerous replication/transcription factor binding sites, enhancer motifs, several perfect or imperfect inverted repeats, and sequences sharing the common features of the potential DNA bending core sequence. The possibility that a combination of different elements in the same DNA sequence may function as either positive or negative regulatory elements in controlling a variety of cellular and developmental processes is discussed.
高等真核生物中的染色体DNA通过特定的基质附着区域（MAR）在其基部周期性地附着于核基质，从而在空间上组织成环状。为了研究将环附着于核基质的DNA序列的性质，我们从牛泌乳乳腺组织中克隆了MAR DNA。体外结合试验表明，克隆的片段可以与核基质蛋白共复合形成不溶性复合物，通过离心很容易去除。所选的两个MAR位点的序列由TG-、CA-和GA-块以及ATTA基序组成。两个MAR位点都显示出许多复制/转录因子结合位点、增强子基序、几个完美或不完美的反向重复序列，以及具有潜在DNA弯曲核心序列共同特征的序列。本文讨论了同一DNA序列中不同元件的组合可能作为正负调控元件来控制各种细胞和发育过程的可能性。
