转录起始的调节对于发育和细胞过程至关重要。RNA聚合酶II(PolII)通过基础转录机制募集到PolII启动转录的核心启动子。核心启动子包含相对于+1转录起始位点(TSS)的-40至+40bp的区域。核心启动子可以包含一个或多个核心启动子基序,这些基序赋予核心启动子特定的特性。比如TATA盒子,位于TSS下游的发起者(Inr)和基序,即,主题10元素(MTE),下游核心启动子元件(DPE)和桥,二分核心启动子元件。我们之前已经证明了考达尔,增强子结合同源域转录因子和Hox基因网络的关键调节因子,是DPE特异性活化剂。有趣的是,成对规则蛋白与扩增位点的增强子-启动子通讯有关。Fushitarazu(Ftz)是由ftz配对规则基因编码的增强子结合同源域转录因子。Ftz与其共同因素协同工作,Ftz-F1,激活转录。这里,我们检查了Ftz和Ftz-F1是否优先于特定的核心启动子基序激活转录。我们的分析表明,类似于卡达尔,Ftz和Ftz-F1将含有TATA盒突变的启动子激活到显著高于含有DPE突变的启动子的水平,因此证明了对DPE图案的偏好。我们进一步发现Ftz靶基因富含果蝇物种中保守的功能性下游核心启动子元件的组合。因此,独特的组合(Inr,Ftz靶基因中功能性下游核心启动子元件的Bridge和DPE)突出了在不同发育基因调控网络的转录中通过核心启动子进行转录调控的复杂性。
The regulation of transcription initiation is critical for developmental and cellular processes. RNA polymerase II (Pol II) is recruited by the basal transcription machinery to the core promoter where Pol II initiates transcription. The core promoter encompasses the region from -40 to +40 bp relative to the +1 transcription start site (TSS). Core promoters may contain one or more core promoter motifs that confer specific properties to the core promoter, such as the TATA box, initiator (Inr) and motifs that are located downstream of the TSS, namely, motif 10 element (MTE), the downstream core promoter element (DPE) and the Bridge, a bipartite core promoter element. We had previously shown that Caudal, an enhancer-binding homeodomain transcription factor and a key regulator of the Hox gene network, is a DPE-specific activator. Interestingly, pair-rule proteins have been implicated in enhancer-promoter communication at the engrailed locus. Fushi tarazu (Ftz) is an enhancer-binding homeodomain transcription factor encoded by the ftz pair-rule gene. Ftz works in concert with its co-factor, Ftz-F1, to activate transcription. Here, we examined whether Ftz and Ftz-F1 activate transcription with a preference for a specific core promoter motif. Our analysis revealed that similarly to Caudal, Ftz and Ftz-F1 activate the promoter containing a TATA box mutation to significantly higher levels than the promoter containing a DPE mutation, thus demonstrating a preference for the DPE motif. We further discovered that Ftz target genes are enriched for a combination of functional downstream core promoter elements that are conserved among Drosophila species. Thus, the unique combination (Inr, Bridge and DPE) of functional downstream core promoter elements within Ftz target genes highlights the complexity of transcriptional regulation via the core promoter in the transcription of different developmental gene regulatory networks.