Biology:MED1

Short description: Protein-coding gene in the species Homo sapiens

Generic protein structure example

Mediator of RNA polymerase II transcription subunit 1 also known as DRIP205 or Trap220 is a subunit of the Mediator complex and is a protein that in humans is encoded by the MED1 gene. MED1 functions as a nuclear receptor coactivator.

Med1
Identifiers
Symbol	Med1
Pfam	PF10744
InterPro	IPR019680
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

Function

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 mediator of RNA polymerase II transcription subunit 1 protein 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 that interact with TR and facilitate TR function on DNA templates in conjunction with initiation factors and cofactors]. It also regulates p53-dependent apoptosis and it is essential for adipogenesis. This protein is known to have the ability to self-oligomerize.

Interactions

MED1 has been shown to interact with:

• Androgen receptor,
• BRCA1,
• Calcitriol receptor,
• Cyclin-dependent kinase 8,
• Estrogen receptor alpha,
• Glucocorticoid receptor,
• Hepatocyte nuclear factor 4 alpha,
• P53,
• PPARGC1A,
• PPARG,
• TGS1, and
• Thyroid hormone receptor alpha.

Protein family

This entry represents subunit Med1 of the Mediator complex. The Med1 forms part of the Med9 submodule of the Srb/Med complex. It is one of three subunits essential for viability of the whole organism via its role in environmentally-directed cell-fate decisions.

Further reading

• "Two classes of proteins dependent on either the presence or absence of thyroid hormone for interaction with the thyroid hormone receptor.". Mol. Endocrinol. 9 (2): 243–54. 1995. doi:10.1210/mend.9.2.7776974. PMID 7776974. 
• "Ligand induction of a transcriptionally active thyroid hormone receptor coactivator complex.". Proc. Natl. Acad. Sci. U.S.A. 93 (16): 8329–33. 1996. doi:10.1073/pnas.93.16.8329. PMID 8710870. Bibcode: 1996PNAS...93.8329F. 
• "Identification of RB18A, a 205 kDa new p53 regulatory protein that shares antigenic and functional properties with p53.". Oncogene 15 (25): 3013–24. 1998. doi:10.1038/sj.onc.1201492. PMID 9444950. 
• "The TRAP220 component of a thyroid hormone receptor- associated protein (TRAP) coactivator complex interacts directly with nuclear receptors in a ligand-dependent fashion.". Proc. Natl. Acad. Sci. U.S.A. 95 (14): 7939–44. 1998. doi:10.1073/pnas.95.14.7939. PMID 9653119. Bibcode: 1998PNAS...95.7939Y. 
• "The transcriptional cofactor complex CRSP is required for activity of the enhancer-binding protein Sp1.". Nature 397 (6718): 446–50. 1999. doi:10.1038/17141. PMID 9989412. Bibcode: 1999Natur.397..446R. 
• "A novel human SRB/MED-containing cofactor complex, SMCC, involved in transcription regulation.". Mol. Cell 3 (1): 97–108. 1999. doi:10.1016/S1097-2765(00)80178-1. PMID 10024883. 
• "Identity between TRAP and SMCC complexes indicates novel pathways for the function of nuclear receptors and diverse mammalian activators.". Mol. Cell 3 (3): 361–70. 1999. doi:10.1016/S1097-2765(00)80463-3. PMID 10198638. 
• "Ligand-dependent transcription activation by nuclear receptors requires the DRIP complex.". Nature 398 (6730): 824–8. 1999. doi:10.1038/19783. PMID 10235266. Bibcode: 1999Natur.398..824R. 
• "Composite co-activator ARC mediates chromatin-directed transcriptional activation.". Nature 398 (6730): 828–32. 1999. doi:10.1038/19789. PMID 10235267. Bibcode: 1999Natur.398..828N. 
• "Coactivators for the orphan nuclear receptor RORalpha.". Mol. Endocrinol. 13 (9): 1550–7. 1999. doi:10.1210/mend.13.9.0343. PMID 10478845. 
• "The DRIP complex and SRC-1/p160 coactivators share similar nuclear receptor-binding determinants but constitute functionally distinct complexes.". Mol. Cell. Biol. 20 (8): 2718–26. 2000. doi:10.1128/MCB.20.8.2718-2726.2000. PMID 10733574. 
• "RB18A, whose gene is localized on chromosome 17q12-q21.1, regulates in vivo p53 transactivating activity.". Cancer Res. 60 (23): 6585–9. 2001. PMID 11118038. 
• "Regulation of glucocorticoid receptor activity by 14--3-3-dependent intracellular relocalization of the corepressor RIP140.". Mol. Endocrinol. 15 (4): 501–11. 2001. doi:10.1210/mend.15.4.0624. PMID 11266503. 
• "Defects of the heart, eye, and megakaryocytes in peroxisome proliferator activator receptor-binding protein (PBP) null embryos implicate GATA family of transcription factors.". J. Biol. Chem. 277 (5): 3585–92. 2002. doi:10.1074/jbc.M107995200. PMID 11724781. 
• "RB18A regulates p53-dependent apoptosis.". Oncogene 21 (6): 861–6. 2002. doi:10.1038/sj.onc.1205177. PMID 11840331. 
• "The TRAP/Mediator coactivator complex interacts directly with estrogen receptors alpha and beta through the TRAP220 subunit and directly enhances estrogen receptor function in vitro.". Proc. Natl. Acad. Sci. U.S.A. 99 (5): 2642–7. 2002. doi:10.1073/pnas.261715899. PMID 11867769. Bibcode: 2002PNAS...99.2642K. 
• "Interaction of PIMT with transcriptional coactivators CBP, p300, and PBP differential role in transcriptional regulation.". J. Biol. Chem. 277 (22): 20011–9. 2002. doi:10.1074/jbc.M201739200. PMID 11912212. 
• "Transcription coactivator TRAP220 is required for PPAR gamma 2-stimulated adipogenesis.". Nature 417 (6888): 563–7. 2002. doi:10.1038/417563a. PMID 12037571. Bibcode: 2002Natur.417..563G. 

This article incorporates text from the public domain Pfam and InterPro: IPR019680