Transcriptional state of line mouse mammary tumor virus promoter can affect topological domain size in vivo
Transcriptional state of line mouse mammary tumor virus promoter can affect topological domain size in vivo
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DOI：
10.1074/jbc.274.40.28590
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发表时间：
1999-10-01
影响因子：
4.8
通讯作者：
Sinden, RR
中科院分区：
文献类型：
--
作者：
Kramer, PR;Fragoso, G;Sinden, RR
不受限制的DNA超螺旋和拓扑结构域的数量进行了测量内的1.8兆碱基对染色体区域组成的约200个串联重复的小鼠乳腺肿瘤病毒启动子驱动的ha-v-ras基因。当未诱导时，不受限制的负超螺旋被组织成32-乙酰化酶对（kb）拓扑结构域。在诱导后，整个区域的DNA超螺旋完全松弛。超螺旋检测，但是，当伸长被阻止之前或之后的诱导。在添加地塞米松后形成的转录起始复合物的结构域大小减少到16 kb。在转录过程中，结构域大小为9 kb，即一个重复序列的长度。这些结果表明，拓扑结构域边界可以是“功能性的”，在性质上，被激活和延长转录复合物的形成建立。
Unrestrained DNA supercoiling and the number of topological domains were measured within a 1.8 megabase pair chromosomal region consisting of about 200 tandem repeats of a mouse mammary tumor virus promoter-driven ha-v-ras gene. When uninduced, unrestrained negative supercoiling was organized into 32-kilobase pair (kb) topological domains. Upon induction, DNA supercoiling throughout the region was completely relaxed. Supercoiling was detected, however, when elongation was blocked before or following induction. The formation of transcription initiation complexes upon addition of dexamethasone decreased the domain size to 16 kb. During transcription the domain size was 9 kb, the length of one repeat. These results suggest that topological domain boundaries can be "functional" in nature, being established by the formation of activated and elongating transcription complexes.