Facultad de Ciencias Biológicas, Departamento de Inmunología y Virología, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México.
Facultad de Ciencias Biológicas, Departamento de Biología Celular y Genética, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México.
Hereditas. 2024 Jul 30;161(1):25. doi: 10.1186/s41065-024-00327-x.
Hox proteins interact with DNA and many other proteins, co-factors, transcriptional factors, chromatin remodeling components, non-coding RNAs and even the extracellular matrix that assembles the Hox complexes. The number of interacting partners continues to grow with diverse components and more transcriptional factors than initially thought. Hox complexes present many activities, but their molecular mechanisms to modulate their target genes remain unsolved.
In this paper we showed the protein-protein interaction of Antp with Ubx through the homeodomain using BiFC in Drosophila. Analysis of Antp-deletional mutants showed that AntpHD helixes 1 and 2 are required for the interaction with Ubx. Also, we found a novel interaction of Ubx with TBP, in which the PolyQ domain of TBP is required for the interaction. Moreover, we also detected the formation of two new trimeric complexes of Antp with Ubx, TBP and Exd using BiFC-FRET; these proteins, however, do not form a trimeric interaction with BIP2 or TFIIEβ. The novel trimeric complexes reduced Antp transcriptional activity, indicating that they could confer specificity for repression.
Our results increase the number of transcriptional factors in the Antp and Ubx interactomes that form two novel trimeric complexes with TBP and Exd. We also report a new Ubx interaction with TBP. These novel interactions provide important clues of the dynamics of Hox-interacting complexes involved in transcriptional regulation, contributing to better understand Hox function.
Hox 蛋白与 DNA 和许多其他蛋白质、辅助因子、转录因子、染色质重塑成分、非编码 RNA 甚至组装 Hox 复合物的细胞外基质相互作用。随着越来越多的转录因子和不同成分的出现，相互作用的伙伴数量不断增加。Hox 复合物具有许多活性，但调节其靶基因的分子机制仍未解决。
在本文中，我们通过双荧光互补（BiFC）在果蝇中显示了 Antp 与 Ubx 通过同源域的蛋白-蛋白相互作用。对 Antp 缺失突变体的分析表明，AntpHD 螺旋 1 和 2 对于与 Ubx 的相互作用是必需的。此外，我们还发现了 Ubx 与 TBP 的新相互作用，其中 TBP 的多聚 Q 结构域对于相互作用是必需的。此外，我们还通过 BiFC-FRET 检测到 Antp 与 Ubx、TBP 和 Exd 形成的两个新的三聚体复合物；然而，这些蛋白质不会与 BIP2 或 TFIIEβ 形成三聚体相互作用。新形成的三聚体复合物降低了 Antp 的转录活性，表明它们可能赋予了抑制的特异性。
我们的研究结果增加了 Antp 和 Ubx 相互作用组中的转录因子数量，这些转录因子与 TBP 和 Exd 形成两个新的三聚体复合物。我们还报告了 Ubx 与 TBP 的新相互作用。这些新的相互作用为参与转录调控的 Hox 相互作用复合物的动力学提供了重要线索，有助于更好地理解 Hox 功能。
