Analysis of the components of a novel coactivator.the NF complex, and its regulatory mechanisms

NF复合物（NF 45-NF 90和NF 45-NF 110）的转录活性由c-fos基因的上游增强子和核心启动子区域介导。小鼠细胞中内源性NF 90/NF 110的敲低导致血清刺激后c-fos转录的诱导减少。染色质免疫沉淀分析表明，NF复合物占据c-fos增强子/启动子区域之前和之后的血清诱导和c-fos基因的编码区内的occupancy增加平行RNAPII血清诱导。因此，NF复合物似乎作为多功能的辅活化剂，协调基因表达的不同步骤，以促进诱导基因的快速反应。

The transcriptional activities of the NF complexes (NF45-NF90 and NF45-NF110) are mediated by both the upstream enhancer and core promoter regions of the c-fos gene. Knockdown of the endogenous NF90/NF110 in mouse cells results in a diminished induction of c-fos transcription upon serum stimulation. Chromatin immunoprecipitation assays show that the NF complexes occupy the c-fos enhancer/promoter region before and after serum induction and that their occupancies within the coding region of the c-fos gene increase in parallel to that of RNAPII upon serum induction. Thus, the NF complexes appear to serve as multifunctional coactivators that coordinate different steps of gene expression to facilitate rapid response of inducible genes.