Interactions between subunits of Drosophila Mediator and activator proteins.
Mediator was first identified because of its activity in activator-stimulated transcription in vivo and in vitro. Later, biochemical fractionation led to the co-purification of the multi-subunit Mediator complex and RNA polymerase II (pol II). Results of these studies suggested a model whereby transcription-activator proteins, which bind to specific gene regulatory sequences, recruit both Mediator and pol II as a holoenzyme in a one-step mechanism. More recent studies of Drosophila Mediator and additional studies in yeast have demonstrated that different transcription activators can bind and recruit Mediator to promoters in vivo in a step that is independent of pol II recruitment. Moreover, the different activators in Drosophila bind and recruit Mediator via physical interactions with specific subsets of proteins. These features of Mediator function seem to be broadly conserved.
Kim
Young-Joon
YJ
Department of Biochemistry, Yonsei University, 134 Sinchon-dong, Seodaemoon-gu, Seoul 120-749, Republic of Korea.
Lis
John T
JT
D000818:Animals; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D008957:Models, Genetic; D021122:Protein Subunits / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic
D029721:Drosophila Proteins; D021122:Protein Subunits; D015534:Trans-Activators; D012319:RNA Polymerase II