MED23
Description
The MED23 (mediator complex subunit 23) is a protein-coding gene located on chromosome 6.
Mediator of RNA polymerase II transcription subunit 23 is an enzyme that in humans is encoded by the MED23 gene. 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. CRSP3 has been shown to interact with Estrogen receptor alpha, CEBPB and Cyclin-dependent kinase 8.
MED23 is essential for transcriptional activation after the pre-initiation complex assembles. It is a component of the Mediator complex, a coactivator involved in regulating the transcription of almost all RNA polymerase II-dependent genes. Mediator acts as a bridge, transferring information from gene-specific regulatory proteins to the core RNA polymerase II transcription machinery. It is recruited to promoters through direct interactions with regulatory proteins, serving as a scaffold for assembling a functional pre-initiation complex with RNA polymerase II and the general transcription factors. It is needed for transcriptional activation by adenovirus E1A protein and for ELK1-dependent transcriptional activation in response to activated Ras signaling.
MED23 is also known as ARC130, CRSP130, CRSP133, CRSP3, DRIP130, MRT18, SUR-2, SUR2.
