Rudolf Virchow Center for Experimental Biomedicine, University of Wuerzburg, Josef-Schneider-Str. 2, 97080, Wuerzburg, Germany.
Sci Rep. 2017 Feb 27;7:43584. doi: 10.1038/srep43584.
Here we present the most comprehensive analysis of the yeast Mediator complex interactome to date. Particularly gentle cell lysis and co-immunopurification conditions allowed us to preserve even transient protein-protein interactions and to comprehensively probe the molecular environment of the Mediator complex in the cell. Metabolic N-labeling thereby enabled stringent discrimination between bona fide interaction partners and nonspecifically captured proteins. Our data indicates a functional role for Mediator beyond transcription initiation. We identified a large number of Mediator-interacting proteins and protein complexes, such as RNA polymerase II, general transcription factors, a large number of transcriptional activators, the SAGA complex, chromatin remodeling complexes, histone chaperones, highly acetylated histones, as well as proteins playing a role in co-transcriptional processes, such as splicing, mRNA decapping and mRNA decay. Moreover, our data provides clear evidence, that the Mediator complex interacts not only with RNA polymerase II, but also with RNA polymerases I and III, and indicates a functional role of the Mediator complex in rRNA processing and ribosome biogenesis.
在这里，我们呈现了迄今为止酵母中介体复合物相互作用组的最全面分析。特别温和的细胞裂解和共免疫沉淀条件使我们能够保留甚至瞬时的蛋白质-蛋白质相互作用，并全面探测细胞中介体复合物的分子环境。代谢 N 标记从而能够严格区分真正的相互作用伙伴和非特异性捕获的蛋白质。我们的数据表明中介体具有转录起始以外的功能作用。我们鉴定了大量的中介体相互作用蛋白和蛋白复合物，如 RNA 聚合酶 II、一般转录因子、大量转录激活因子、SAGA 复合物、染色质重塑复合物、组蛋白伴侣、高度乙酰化的组蛋白，以及在转录过程中发挥作用的蛋白，如剪接、mRNA 去帽和 mRNA 衰变。此外，我们的数据提供了明确的证据，表明中介体复合物不仅与 RNA 聚合酶 II 相互作用，而且与 RNA 聚合酶 I 和 III 相互作用，并表明中介体复合物在 rRNA 加工和核糖体生物发生中的功能作用。
