Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, 10 Lavrentieva Street, Novosibirsk 630090, Russian Federation.
Gene. 2013 May 15;520(2):178-84. doi: 10.1016/j.gene.2013.02.012. Epub 2013 Feb 26.
It is known that a lot of genes having a distinct expression pattern require the complex system of transcription regulation. The regulatory regions of such genes can include not only the 5'-flanking regions, but also other regions, particularly their intron sequences. The Drosophila melanogaster Trithorax-like (Trl) gene, encoding the GAGA protein, is one of the genes with complex expression pattern. GAGA is one of a few transcription factors that can regulate gene expression at multiple levels. The GAGA-mediated modulation of expression seems to be linked with modifications of the chromatin structure. Nowadays, the regulatory potential of the Trl 5'-flanking region that contains multiple GAGA binding sites has been analyzed, but the presence of the functionally significant elements in other Trl regions has not been examined. We found DNase I hypersensitive sites, evolutionary-conserved sequences and numerous GAGA binding sites in the second intron of the Trl gene. Interestingly, these sequences localize in two main regions of the intron in immediate proximity to preferred regions of transposon insertions. Additionally, we revealed that deletion of the intron fragment in the Trl(1-72) mutants caused an alteration of the Trl expression pattern. These results allow us to conclude that the second intron of the Trl gene contains functionally significant elements.
已知许多具有独特表达模式的基因需要复杂的转录调控系统。这些基因的调控区域不仅包括 5'侧翼区域，还包括其他区域，特别是它们的内含子序列。果蝇 melanogaster 的 Trithorax-like (Trl) 基因，编码 GAGA 蛋白，是具有复杂表达模式的基因之一。GAGA 是少数几种可以在多个水平上调节基因表达的转录因子之一。GAGA 介导的表达调控似乎与染色质结构的修饰有关。如今，已经分析了包含多个 GAGA 结合位点的 Trl 5'侧翼区的调控潜力，但尚未检查其他 Trl 区域中功能重要的元件的存在。我们在 Trl 基因的第二个内含子中发现了 DNase I 超敏位点、进化保守序列和许多 GAGA 结合位点。有趣的是，这些序列位于内含子的两个主要区域内，紧邻转座子插入的首选区域。此外，我们还揭示了 Trl(1-72)突变体中内含子片段的缺失导致了 Trl 表达模式的改变。这些结果使我们得出结论，Trl 基因的第二个内含子包含功能重要的元件。
