Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia.
Group of Dynamics of Transcriptional Complexes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
Cell Mol Life Sci. 2022 Jun 9;79(7):353. doi: 10.1007/s00018-022-04383-2.
The Polycomb group (PcG) and Trithorax group (TrxG) proteins are key epigenetic regulators controlling the silenced and active states of genes in multicellular organisms, respectively. In Drosophila, PcG/TrxG proteins are recruited to the chromatin via binding to specific DNA sequences termed polycomb response elements (PREs). While precise mechanisms of the PcG/TrxG protein recruitment remain unknown, the important role is suggested to belong to sequence-specific DNA-binding factors. At the same time, it was demonstrated that the PRE DNA-binding proteins are not exclusively localized to PREs but can bind other DNA regulatory elements, including enhancers, promoters, and boundaries. To gain an insight into the PRE DNA-binding protein regulatory network, here, using ChIP-seq and immuno-affinity purification coupled to the high-throughput mass spectrometry, we searched for differences in abundance of the Combgap, Zeste, Psq, and Adf1 PRE DNA-binding proteins. While there were no conspicuous differences in co-localization of these proteins with other functional transcription factors, we show that Combgap and Zeste are more tightly associated with the Polycomb repressive complex 1 (PRC1), while Psq interacts strongly with the TrxG proteins, including the BAP SWI/SNF complex. The Adf1 interactome contained Mediator subunits as the top interactors. In addition, Combgap efficiently interacted with AGO2, NELF, and TFIID. Combgap, Psq, and Adf1 have architectural proteins in their networks. We further investigated the existence of direct interactions between different PRE DNA-binding proteins and demonstrated that Combgap-Adf1, Psq-Dsp1, and Pho-Spps can interact in the yeast two-hybrid assay. Overall, our data suggest that Combgap, Psq, Zeste, and Adf1 are associated with the protein complexes implicated in different regulatory activities and indicate their potential multifunctional role in the regulation of transcription.
多梳抑制复合物（PcG）和三价基因激活复合物（TrxG）蛋白分别是多细胞生物中控制基因沉默和激活状态的关键表观遗传调控因子。在果蝇中，PcG/TrxG 蛋白通过结合特定的 DNA 序列（称为多梳反应元件（PREs））被募集到染色质上。虽然 PcG/TrxG 蛋白募集的确切机制尚不清楚，但认为其重要作用属于序列特异性 DNA 结合因子。同时，已经证明 PRE DNA 结合蛋白不仅局限于 PREs 上，还可以结合其他 DNA 调节元件，包括增强子、启动子和边界。为了深入了解 PRE DNA 结合蛋白的调控网络，在这里，我们使用 ChIP-seq 和免疫亲和纯化结合高通量质谱，搜索 Combgap、Zeste、Psq 和 Adf1 PRE DNA 结合蛋白丰度的差异。虽然这些蛋白与其他功能转录因子的共定位没有明显差异，但我们表明 Combgap 和 Zeste 与多梳抑制复合物 1（PRC1）的结合更为紧密，而 Psq 与包括 BAP SWI/SNF 复合物在内的 TrxG 蛋白强烈相互作用。Adf1 相互作用组包含 Mediator 亚基作为顶级相互作用物。此外，Combgap 还与 AGO2、NELF 和 TFIID 有效地相互作用。Combgap、Psq 和 Adf1 在其网络中具有结构蛋白。我们进一步研究了不同 PRE DNA 结合蛋白之间是否存在直接相互作用，并证明在酵母双杂交测定中，Combgap-Adf1、Psq-Dsp1 和 Pho-Spps 可以相互作用。总的来说，我们的数据表明，Combgap、Psq、Zeste 和 Adf1 与涉及不同调节活性的蛋白复合物相关，并表明它们在转录调控中具有潜在的多功能作用。
