Coactivators and Corepressors

At the vast majority of eukaryotic promoters, transcription is mediated by RNA polymerase II (RNA pol II). Activated transcription at these promoters is believed to require assembly of a transcriptional preinitiation complex, comprising general transcription factors (GTFs) such as TFIIB, TFIID, a multicomponent complex composed of TATA binding protein (TBP) and the TBP-associated factors (TAF ii s), as well as RNA pol II itself. In many cases, the net rate of assembly of such complexes is enhanced by transcription factors that bind specific recognition sequences within promoters. Functional interactions between activated transcription factors and general transcription factors are thought to be mediated by coactivators , which may be broadly defined as molecules recruited by transcription factors to enhance their transcriptional activity. Within this definition lies a wide range of functions that together are required for efficient activation by transcription factors. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.