中文摘要：

中介体复合物作为转录过程中的重要辅因子，广泛参与TRNA聚合酶II（RNA polymeraseⅡ，pol Ⅱ）调控的转录激活与抑制过程，其结构在进化上具有保守性。然而，由于中介体复合物结构与组成的复杂性和可变性，我们对其调控基因表达的机制仍知之甚少。最近研究显示中介体复合物多种转录活性的调节与转变，可能与细胞周期素依赖性激酶8（cyclin-dependent kinase 8，CDK8）亚模块的可逆性结合与修饰密切相关。

英文摘要：

The mediator complex is an evolutionarily conserved transcriptional regulator which plays vital roles in repressing and activating KNA polymerase Ⅱ （pol Ⅱ） transcription. However, the mechanisms by which mediator regulates gene expression remain poorly understood due to its complex structure and even variable composition. From progress in current studies, the absence or presence of the cyclin-dependent kinase 8 （CDK8） and modification of CDK8 in mediator have been shown to be important in mediator＇s variable and multiple functions in transcription. Here, our review gives a comprehensive summary of research progress on mediator complex and presents the prospects of it.