背景:Hox蛋白与DNA和许多其他蛋白相互作用,共同因素,转录因子,染色质重塑成分,非编码RNA,甚至是组装Hox复合物的细胞外基质。相互作用的伴侣的数量继续增长,与最初认为的不同成分和更多的转录因子。Hox建筑群有许多活动,但它们调节靶基因的分子机制仍未解决。
结果:在本文中,我们在果蝇中使用BiFC通过同源结构域显示了Antp与Ubx的蛋白质-蛋白质相互作用。对Antp缺失突变体的分析表明,与Ubx相互作用需要AntpHD螺旋1和2。此外,我们发现了Ubx与TBP的新相互作用,其中TBP的PolyQ域是相互作用所必需的。此外,我们还检测到Antp与Ubx的两个新的三聚体复合物的形成,使用BiFC-FRET的TBP和Exd;这些蛋白质,然而,不与BIP2或TFIIEβ形成三聚体相互作用。新的三聚体复合物降低了Antp转录活性,表明它们可以赋予抑制的特异性。
结论:我们的结果增加了与TBP和Exd形成两个新的三聚体复合物的Antp和Ubx中间细胞中转录因子的数量。我们还报告了一种新的Ubx与TBP的相互作用。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。
BACKGROUND: 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.
RESULTS: 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.
CONCLUSIONS: 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.