牛乳腺核基质附着区多重顺式作用序列表明其功能的多样性(英文)  

Multiple Cis-acting Sequences Implicate Function Diversity in Nuclear Matrix Attachment Regions of Bovine Mammary Gland

作　　者：劳为德[1] 张传生[1] 胡国法[1] 张旭晨[1] 魏影允[1] 

机构地区：[1]中国科学院遗传与发育生物学研究所,北京100080

出　　处：《Acta Genetica Sinica》2003年第5期397-406,共10页

基　　金：中国科学院知识创新工程项目 (KSCX- 0 5- 0 3)~~

摘　　要：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MARDNA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。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.

关 键 词：基质 基质附着区 转录因子 

分 类 号：Q953[生物学—动物学]