CAJ | 학술논문

高等真核细胞的染色体DNA通过基质结合区(MAR)不时地与核基质特异性结合而组织成一种空间环状结构.为了研究以DNA套环形式附着于核基质上的DNA序列的特性,从处于泌乳期的乳腺组织中克隆了多个MAR DNA 序列.体外结合实验表明,这些序列能够同核基质蛋白共结合成不溶性的复合物,这些复合物可较容易的通过离心去除.其中,两个MAR序列中包含有TG-、CA-和GA-阻断以及ATTA基序.这两个序列中含有多个复制/转录因子的结合位点、增强子基序、多个完全的和非完全的反向重复序列以及潜在的DNA弯曲核心序列样结构.同一DNA序列中存在不同元件的组合可能说明在控制一系列细胞的发育过程中,它们可能发挥有正的或负的调控元件的功能.
고등진핵세포적염색체DNA통과기질결합구(MAR)불시지여핵기질특이성결합이조직성일충공간배상결구.위료연구이DNA투배형식부착우핵기질상적DNA서렬적특성,종처우비유기적유선조직중극륭료다개MAR DNA 서렬.체외결합실험표명,저사서렬능구동핵기질단백공결합성불용성적복합물,저사복합물가교용역적통과리심거제.기중,량개MAR서렬중포함유TG-、CA-화GA-조단이급ATTA기서.저량개서렬중함유다개복제/전록인자적결합위점、증강자기서、다개완전적화비완전적반향중복서렬이급잠재적DNA만곡핵심서렬양결구.동일DNA서렬중존재불동원건적조합가능설명재공제일계렬세포적발육과정중,타문가능발휘유정적혹부적조공원건적공능.
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 controling a variety of cellular and developmental processes is discussed.