Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia.
Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 119334, Russia.
Int J Mol Sci. 2023 Jul 12;24(14):11368. doi: 10.3390/ijms241411368.
In higher eukaryotes, distance enhancer-promoter interactions are organized by topologically associated domains, tethering elements, and chromatin insulators/boundaries. While insulators/boundaries play a central role in chromosome organization, the mechanisms regulating their functions are largely unknown. In the studies reported here, we have taken advantage of the well-characterized bithorax complex (BX-C) to study one potential mechanism for controlling boundary function. The regulatory domains of BX-C are flanked by boundaries, which block crosstalk with their neighboring domains and also support long-distance interactions between the regulatory domains and their target gene. As many lncRNAs have been found in BX-C, we asked whether readthrough transcription (RT) can impact boundary function. For this purpose, we took advantage of two BX-C boundary replacement platforms, and , in which the and boundaries, respectively, are deleted and replaced with an site. We introduced boundary elements, promoters, and polyadenylation signals arranged in different combinations and then assayed for boundary function. Our results show that RT can interfere with boundary activity. Since lncRNAs represent a significant fraction of Pol II transcripts in multicellular eukaryotes, it is therefore possible that RT may be a widely used mechanism to alter boundary function and regulation of gene expression.
在高等真核生物中，远距离增强子-启动子相互作用是由拓扑相关结构域、连接元件和染色质绝缘子/边界组织的。虽然绝缘子/边界在染色体组织中起着核心作用，但调节它们功能的机制在很大程度上是未知的。在本研究中，我们利用已充分研究的双胸复合体（BX-C）来研究一种潜在的控制边界功能的机制。BX-C 的调控域被边界包围，这些边界阻止与相邻域的串扰，并支持调控域与其靶基因之间的远距离相互作用。由于在 BX-C 中发现了许多 lncRNA，我们想知道通读转录（RT）是否会影响边界功能。为此，我们利用了两个 BX-C 边界替换平台和，其中分别缺失和替换为一个 位点。我们引入了不同组合排列的边界元件、启动子和聚腺苷酸化信号，并检测了边界功能。我们的结果表明，RT 可以干扰边界活性。由于 lncRNA 代表了多细胞真核生物中 Pol II 转录物的重要组成部分，因此 RT 可能是一种广泛用于改变边界功能和基因表达调控的机制。
