Casamassimi Amelia, Napoli Claudio
Department of General Pathology, Division of Clinical Pathology, 1st School of Medicine, II University of Naples, Via L. De Crecchio 7, 80138-Naples, Italy.
Biochimie. 2007 Dec;89(12):1439-46. doi: 10.1016/j.biochi.2007.08.002. Epub 2007 Aug 11.
Mediator is an essential component of the RNA polymerase II-mediated transcription machinery. This component plays a key role both in the stimulation of basal transcription and in the regulation of eukaryotic mRNA synthesis. The Saccharomyces cerevisiae Mediator complex was the first to be studied and consists of at least 20 different subunits with multiple activities. Afterwards, its subunit composition was determined and related functions of C. elegans, Drosophila and mammalian complexes show a striking evolutionary conservation both of the structure and function from yeast to man. Recently, yeast studies strongly suggest additional roles for Mediator in coordinating transcription initiation with downstream transcriptional events in the coding region of genes; consequently, new models of recruitment-coupled regulation have been indicated. Further studies on transcription machinery should expand our knowledge of the pathways in which variant components of Mediator, or variant proteins interacting directly or in complexes, represent risk factors for complex inheritable disease.
中介体是RNA聚合酶II介导的转录机制的重要组成部分。该组成部分在基础转录的刺激以及真核mRNA合成的调控中均发挥关键作用。酿酒酵母中介体复合物是首个被研究的，它由至少20个具有多种活性的不同亚基组成。之后，其亚基组成得以确定，秀丽隐杆线虫、果蝇和哺乳动物复合物的相关功能显示出从酵母到人类在结构和功能上惊人的进化保守性。最近，酵母研究有力地表明中介体在协调基因编码区转录起始与下游转录事件方面还有其他作用；因此，已经提出了募集偶联调控的新模型。对转录机制的进一步研究应能扩展我们对中介体变体成分，或直接或以复合物形式相互作用的变体蛋白作为复杂遗传性疾病风险因素的相关途径的认识。
