Alternative titles; symbols
HGNC Approved Gene Symbol: MED7
Cytogenetic location: 5q33.3 Genomic coordinates (GRCh38) : 5:157,137,424-157,142,865 (from NCBI)
The Mediator is a multiprotein coactivator that is required by DNA-binding transcription factors for activation of polymerase II (see 180660)-transcribed genes. MED7 appears to be a core Mediator subunit and is found in nearly all Mediator preparations (summary by Sato et al., 2004).
Gene transcription requires factors that recognize transcriptional enhancer sites in DNA. These factors work with coactivators to direct transcriptional initiation by the RNA polymerase II apparatus (see POLR2A; 180660). Transcriptional activation by enhancer-binding factors such as SP1 (189906) requires interaction with the TFIID complex (see TAF2A, 313650). To identify other potential SP1 cofactors, Ryu et al. (1999) developed an in vitro transcription assay consisting of TFIIA (GTF2A1; 600520), RNA polII, and the basal transcription factors GTF2B (189963), GTF2E (189962), GTF2F (189968), and GTF2H (189972), supplemented with TFIID or TBP (600075). By sequential chromatography, they excluded PC4 (600503) as an SP1 cofactor and identified a multisubunit cofactor, CRSP (cofactor required for SP1 activation), which, along with TFIID, is required for efficient activation by SP1. CRSP behaves as a single complex of approximately 700 kD. Ryu et al. (1999) tentatively identified 9 polypeptides as CRSP subunits (see also PPARBP; 604311). Using microsequence peptide analysis, they cloned a CRSP cDNA encoding a 33-kD protein, CRSP9, which they termed CRSP34. CRSP9 is identical to a homolog of yeast Med7, which was identified by Myers et al. (1998).
The International Radiation Hybrid Mapping Consortium mapped the MED7 gene to chromosome 5 (NIB574).
Myers, L. C., Gustafsson, c. M., Bushnell, D. A., Lui, M., Erdjument-Bromage, H., Tempst, P., Kornberg, R. D. The Med proteins of yeast and their function through the RNA polymerase II carboxy-terminal domain. Genes Dev. 12: 45-54, 1998. [PubMed: 9420330] [Full Text: https://doi.org/10.1101/gad.12.1.45]
Ryu, S., Zhou, S., Ladurner, A. G., Tjian, R. The transcriptional cofactor complex CRSP is required for activity of the enhancer-binding protein Sp1. Nature 397: 446-450, 1999. [PubMed: 9989412] [Full Text: https://doi.org/10.1038/17141]
Sato, S., Tomomori-Sato, C., Parmely, T. J., Florens, L., Zybailov, B., Swanson, S. K., Banks, C. A. S., Jin, J., Cai, Y., Washburn, M. P., Conaway, J. W., Conaway, R. C. A set of consensus mammalian mediator subunits identified by multidimensional protein identification technology. Molec. Cell 14: 685-691, 2004. [PubMed: 15175163] [Full Text: https://doi.org/10.1016/j.molcel.2004.05.006]