Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
PLoS One. 2018 Feb 23;13(2):e0193497. doi: 10.1371/journal.pone.0193497. eCollection 2018.
Su(Hw) belongs to the class of proteins that organize chromosome architecture and boundaries/insulators between regulatory domains. This protein contains a cluster of 12 zinc finger domains most of which are responsible for binding to three different modules in the consensus site. Su(Hw) forms a complex with CP190 and Mod(mdg4)-67.2 proteins that binds to well-known Drosophila insulators. To understand how Su(Hw) performs its activities and binds to specific sites in chromatin, we have examined the previously described su(Hw)f mutation that disrupts the 10th zinc finger (ZF10) responsible for Su(Hw) binding to the upstream module. The results have shown that Su(Hw)f loses the ability to interact with CP190 in the absence of DNA. In contrast, complete deletion of ZF10 does not prevent the interaction between Su(Hw)Δ10 and CP190. Having studied insulator complex formation in different mutant backgrounds, we conclude that both association with CP190 and Mod(mdg4)-67.2 partners and proper organization of DNA binding site are essential for the efficient recruitment of the Su(Hw) complex to chromatin insulators.
Su(Hw) 属于一类能够组织染色体结构和调控区域之间的边界/绝缘子的蛋白质。该蛋白包含一个簇的 12 个锌指结构域，其中大多数负责结合到共识位点中的三个不同模块。Su(Hw) 与 CP190 和 Mod(mdg4)-67.2 蛋白形成复合物，该复合物与著名的果蝇绝缘子结合。为了了解 Su(Hw) 如何发挥其活性并结合染色质中的特定位点，我们研究了先前描述的 su(Hw)f 突变，该突变破坏了第 10 个锌指 (ZF10)，该锌指负责 Su(Hw) 与上游模块的结合。结果表明，Su(Hw)f 在没有 DNA 的情况下失去了与 CP190 相互作用的能力。相比之下，完全删除 ZF10 并不会阻止 Su(Hw)Δ10 与 CP190 之间的相互作用。在研究不同突变背景下的绝缘子复合物形成后，我们得出结论，与 CP190 和 Mod(mdg4)-67.2 伙伴的结合以及 DNA 结合位点的适当组织对于 Su(Hw) 复合物有效地招募到染色质绝缘子是必不可少的。
