Mediator of RNA polymerase II transcription subunit 23 is an enzyme that in humans is encoded by the MED23gene.
The activation of gene transcription is a multistep process that is triggered by factors that recognize transcriptional enhancer sites in DNA. These factors work with co-activators to direct transcriptional initiation by the RNA polymerase II apparatus. The protein encoded by this gene is a subunit of the CRSP (cofactor required for SP1 activation) complex, which, along with TFIID, is required for efficient activation by SP1. This protein is also a component of other multisubunit complexes e.g. thyroid hormone receptor-(TR-) associated proteins which interact with TR and facilitate TR function on DNA templates in conjunction with initiation factors and cofactors. This protein also acts as a metastasis suppressor. Two alternatively spliced transcript variants encoding different isoforms have been described for this gene.
^Ryu S, Zhou S, Ladurner AG, Tjian R (Feb 1999). "The transcriptional cofactor complex CRSP is required for activity of the enhancer-binding protein Sp1". Nature397 (6718): 446–50. doi:10.1038/17141. PMID9989412.
Boyer TG, Martin ME, Lees E et al. (1999). "Mammalian Srb/Mediator complex is targeted by adenovirus E1A protein.". Nature399 (6733): 276–9. doi:10.1038/20466. PMID10353252.
Nagase T, Ishikawa K, Kikuno R et al. (2000). "Prediction of the coding sequences of unidentified human genes. XV. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro.". DNA Res.6 (5): 337–45. doi:10.1093/dnares/6.5.337. PMID10574462.
Sato S, Tomomori-Sato C, Banks CA et al. (2004). "A mammalian homolog of Drosophila melanogaster transcriptional coactivator intersex is a subunit of the mammalian Mediator complex.". J. Biol. Chem.278 (50): 49671–4. doi:10.1074/jbc.C300444200. PMID14576168.
Tomomori-Sato C, Sato S, Parmely TJ et al. (2004). "A mammalian mediator subunit that shares properties with Saccharomyces cerevisiae mediator subunit Cse2.". J. Biol. Chem.279 (7): 5846–51. doi:10.1074/jbc.M312523200. PMID14638676.
Sato S, Tomomori-Sato C, Parmely TJ et al. (2004). "A set of consensus mammalian mediator subunits identified by multidimensional protein identification technology.". Mol. Cell14 (5): 685–91. doi:10.1016/j.molcel.2004.05.006. PMID15175163.
Wada O, Oishi H, Takada I et al. (2004). "BRCA1 function mediates a TRAP/DRIP complex through direct interaction with TRAP220.". Oncogene23 (35): 6000–5. doi:10.1038/sj.onc.1207786. PMID15208681.