Origins and activity of the Mediator complex

Semin Cell Dev Biol. 2011 Sep;22(7):729-34. doi: 10.1016/j.semcdb.2011.07.021. Epub 2011 Jul 28.


The Mediator is a large, multisubunit RNA polymerase II transcriptional regulator that was first identified in Saccharomyces cerevisiae as a factor required for responsiveness of Pol II and the general initiation factors to DNA binding transactivators. Since its discovery in yeast, Mediator has been shown to be an integral and highly evolutionarily conserved component of the Pol II transcriptional machinery with critical roles in multiple stages of transcription, from regulation of assembly of the Pol II initiation complex to regulation of Pol II elongation. Here we provide a brief overview of the evolutionary origins of Mediator, its subunit composition, and its remarkably diverse collection of activities in Pol II transcription.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Evolution, Molecular
  • Gene Expression Regulation
  • Humans
  • Mediator Complex / chemistry
  • Mediator Complex / genetics
  • Mediator Complex / metabolism*
  • Plant Physiological Phenomena
  • Promoter Regions, Genetic
  • Protein Biosynthesis
  • RNA Polymerase II / biosynthesis
  • RNA Polymerase II / genetics
  • RNA Polymerase II / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Transcription, Genetic*


  • Mediator Complex
  • Saccharomyces cerevisiae Proteins
  • RNA Polymerase II