INDUCTION OF RNA-STABILIZED DNA CONFORMERS BY TRANSCRIPTION OF AN IMMUNOGLOBULIN SWITCH REGION
INDUCTION OF RNA-STABILIZED DNA CONFORMERS BY TRANSCRIPTION OF AN IMMUNOGLOBULIN SWITCH REGION
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DOI：
10.1038/348342a0
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发表时间：
1990-11-22
期刊：
影响因子：
64.8
通讯作者：
GRIFFIN, JA
中科院分区：
文献类型：
--
作者：
REABAN, ME;GRIFFIN, JA
缺失 DNA 重排与免疫球蛋白类别从 IgM 转换为 IgG、IgA 或 IgE 相关（参考文献 1 中进行了综述）。这种重组发生在免疫球蛋白开关区域，这是复杂的、高度重复的 DNA 区域。当开关区域在开关重组之前变得转录活跃2,3时，对这些序列在转录过程中的行为进行分析可以阐明开关重组的机制。在这里，我们报告含有鼠 IgA 转换区 (Sα) 的超螺旋质粒的转录导致超螺旋转数的丢失。由此产生的一系列超螺旋较少的质粒通过新生 RNA 转录物形成的 RNA-DNA 杂交体而稳定，这些转录物与其 DNA 模板保持碱基配对。
A DELETIONAL DNA rearrangement is associated with immunoglobulin class switching from IgM to IgG, IgA or IgE (reviewed in ref. 1). This recombination occurs in immunoglobulin switch regions, which are complex, highly repetitive regions of DNA. As switch regions become transcriptionally active2,3just before switch recombination, analysis of the behaviour of these sequences during transcription could elucidate the mechanism of switch recombination. Here, we report that transcription of a supercoiled plasmid containing the murine IgA switch region (Sα)leads to a loss of superhelical turns. The resulting series of less supercoiled plasmids is stabilized by RNA-DNA hybrids formed by the nascent RNA transcripts, which remain base-paired with their DNA templates.