| 1998 |
TRAP220 (MED1) directly interacts with thyroid hormone receptor alpha (TRα) in a ligand-dependent manner, mediated through the C terminus of TRα and the LXXLL domains of TRAP220; it also shows ligand-dependent interactions with VDR, RARα, RXRα, PPARα, PPARγ, and ER. A fragment containing the LXXLL motifs acts as a dominant negative inhibitor of nuclear receptor-mediated transcription both in transfected cells and cell-free transcription systems. |
GST pulldown, co-immunoprecipitation, cell-free transcription assay, transfection/dominant-negative analysis |
Proceedings of the National Academy of Sciences of the United States of America |
High |
9653119
|
| 2000 |
Each of the two LXXLL-containing receptor binding domains (RBD-1 and RBD-2) of TRAP220 is differentially preferred by specific nuclear receptors: RXR prefers RBD-1, while TR, VDR, and PPARs strongly prefer RBD-2 in an AF2-dependent manner. Preference for RBD-2 is determined by basic-polar residues N-terminal to the LXXLL core. Both RBD-1 and RBD-2 are required for optimal association of TRAP220 with RXR-TR or RXR-VDR heterodimers on DNA. |
Site-directed mutagenesis, GST pulldown with recombinant proteins, in vitro transcription assay |
Molecular and cellular biology |
High |
10891484
|
| 2000 |
TRAP220 (MED1) is an essential component required for mouse development; Trap220-null mice die during early gestation with heart failure and impaired neuronal development. Primary embryonic fibroblasts from null mutants show impaired cell cycle regulation and a prominent decrease of thyroid hormone receptor function that is restored by ectopic TRAP220, but no defect in activation by Gal4-RARα/RXRα, p53, or VP16, indicating activator-selective function. |
Gene knockout (null mice), primary embryonic fibroblast rescue experiments, cell-free transcription assay |
Molecular cell |
High |
10882104
|
| 2002 |
TRAP220 (MED1) is required for PPARγ2-stimulated adipogenesis but not MyoD-stimulated myogenesis. Trap220−/− fibroblasts fail to express adipogenesis markers or PPARγ2 target genes; this is restored by exogenous TRAP220. The TRAP/Mediator complex functions directly as a transcriptional coactivator for PPARγ2 in a purified in vitro system and interacts with PPARγ2 in a ligand- and TRAP220-dependent manner. |
Knockout fibroblast differentiation assay, rescue by ectopic expression, purified in vitro transcription system, co-immunoprecipitation |
Nature |
High |
12037571
|
| 2002 |
The TRAP/Mediator complex interacts with ERα and ERβ through TRAP220 in a ligand (17β-estradiol)-dependent manner; this interaction requires TRAP220 as shown using TRAP220−/− fibroblast extracts. An ERα–TRAP/Mediator complex was isolated from cultured cells expressing epitope-tagged ERα. The complete TRAP/Mediator complex directly enhances ER function in a highly purified cell-free transcription system. |
Affinity pulldown from nuclear extracts, co-immunoprecipitation from cells, TRAP220−/− fibroblast extracts, purified in vitro transcription system |
Proceedings of the National Academy of Sciences of the United States of America |
High |
11867769
|
| 2001 |
TRAP220 displays ERβ preference over ERα for recruitment, attributable to the binding specificity of the TRAP220 LXXLL motifs; the ER subtype-specific F-domain influences TRAP220 interaction. |
GST pulldown interaction assays, mutational analysis of LXXLL motifs |
The Journal of biological chemistry |
Medium |
11303023
|
| 2003 |
An extended 13-amino-acid LXXLL motif sequence (not just the 5-residue core) determines the nuclear receptor binding specificity of TRAP220. Swapping extended LXM sequences between TRAP220 and SRC1 alters NR binding preferences. |
GST pulldown interaction assays, mutagenesis of LXXLL flanking regions |
The Journal of biological chemistry |
Medium |
12556447
|
| 2004 |
The N terminus of TRAP220 (MED1) is necessary and sufficient for stable association with the TRAP/Mediator complex, while both LXXLL (NR box) motifs are required for nuclear receptor (TR)-dependent transcription. Trap220−/− cells possess a relatively intact TRAP/Mediator complex that is specifically compromised in TR-dependent but not VP16-dependent transcription in vitro. |
Biochemical fractionation, transfection of TRAP220 deletion/point mutants in null cells, in vitro transcription assay with reconstituted complexes |
Molecular and cellular biology |
High |
15340084
|
| 2005 |
MED1/TRAP220 exists predominantly (>80% of total) in a TRAP/Mediator subpopulation that is enriched in specific subunits and tightly associated with near-stoichiometric RNA polymerase II. This MED1-containing holoenzyme supports basal- and activator-dependent transcription in vitro. MED1/TRAP220-containing versus MED1/TRAP220-deficient complexes are selectively recruited to ER versus p53 target genes. RNAi knockdown of MED1 is required for ER-mediated transcription and estrogen-dependent breast cancer cell growth. |
Biochemical fractionation/mass spectrometry, in vitro transcription, chromatin immunoprecipitation, RNAi knockdown |
Molecular cell |
High |
15989967
|
| 2005 |
ERK (MAPK) phosphorylates TRAP220/MED1 in vivo at two specific sites: threonine 1032 and threonine 1457. ERK phosphorylation increases the stability and half-life of TRAP220/MED1, correlates with increased thyroid hormone receptor-dependent transcription, occurs in a cell cycle-dependent manner (peak at G2/M), and triggers shuttling into the nucleolus. |
In vivo phosphorylation mapping, cell cycle synchronization, in vitro kinase assay, transcription reporter assay |
Molecular and cellular biology |
High |
16314496
|
| 2005 |
In Med1/Trap220-null cells, thyroid hormone (T3)-induced chromatin remodeling events at the Crabp1 locus — including juxtaposition of the TRE and GC box regions, nucleosome sliding, replacement of BRM by BRG1, and histone hyperacetylation — are all abolished, indicating a key role for TRAP/Mediator in these processes. A MED1/TRAP220-containing Mediator complex constitutively occupies the GC box region, serving as a nexus for distal and proximal factors. |
Chromatin immunoprecipitation, null cell genetics, chromatin remodeling assay |
Molecular cell |
High |
16137621
|
| 2005 |
MED1 (MED14 and MED1) are used by glucocorticoid receptor (GR) in a gene-specific manner: ladinin 1 and IRF8 induction requires both MED1 and MED14, IGFBP1 induction requires MED14 but not MED1, and GILZ induction is largely independent of both. |
siRNA knockdown in U2OS-hGR cells, RT-PCR of endogenous GR target genes, ChIP |
Molecular endocrinology (Baltimore, Md.) |
Medium |
16239257
|
| 2006 |
Mediator subunit Med1/TRAP220 physically interacts with the erythroid master regulator GATA-1 and is required for GATA-1-mediated transactivation. Med1-deficient embryos are anemic with defects in erythroid burst-forming units and colony-forming units but not in myeloid colonies. Mediator components occupy GATA-1-occupied enhancer sites by ChIP. |
Co-immunoprecipitation, transactivation assay in Med1-null cells, colony formation assay from Med1-null embryos, chromatin immunoprecipitation |
Proceedings of the National Academy of Sciences of the United States of America |
High |
17132730
|
| 2008 |
ERK phosphorylation of MED1 promotes its association with the Mediator complex via direct binding to the MED7 subunit; ERK phosphorylation enhances the MED1–MED7 interaction. Both thyroid and steroid hormones stimulate MED1 phosphorylation in vivo, and MED1 phosphorylation is required for its nuclear hormone receptor coactivator activity. ERK phosphorylation of MED1 enhances TR-dependent transcription in vitro. |
Co-immunoprecipitation of MED1 with MED7, in vivo phosphorylation by hormone treatment, in vitro transcription assay, phosphorylation-deficient mutants |
Molecular and cellular biology |
High |
18391015
|
| 2008 |
Med1 subunit of the Mediator complex is required for IFN-γ-induced C/EBPβ-driven transcription. Med1 associates with C/EBPβ through a domain located between amino acids 125 and 155 of its N-terminus; ERK1/2-mediated phosphorylation of C/EBPβ at Thr189 is essential for its binding to Med1, and an ERK-regulated site in Med1 is required for IFN-induced transcription. |
Co-immunoprecipitation, Med1 knockout cells, RNAi, mutagenesis of binding and phosphorylation sites |
The Journal of biological chemistry |
Medium |
18339625
|
| 2009 |
PGC-1α is recruited to the TRα–RXRα–UCP-1 enhancer complex through interaction of an N-terminal LXXLL domain with TRα. MED1/Mediator then displaces PGC-1α from TRα through LXXLL domain competition; upon displacement, PGC-1α remains associated with the enhancer through an interaction between PGC-1α and MED1 C-terminal domains. Med1 is required for UCP-1 induction in brown adipocytes. |
Biochemical competition assays, co-immunoprecipitation, chromatin immunoprecipitation, Med1 RNAi in primary brown adipocytes |
Molecular cell |
High |
19782026
|
| 2010 |
MED1 LxxLL motif knockin mice exhibit severe defects in pubertal mammary gland development with loss of ERα-Mediator interaction, down-regulation of ERα-regulated genes, and impaired mammary luminal epithelial cell differentiation. MED1 is differentially expressed in different types of mammary epithelial cells. |
Knockin mouse model (LxxLL motif mutations), mammary gland histology, gene expression analysis, ChIP |
Proceedings of the National Academy of Sciences of the United States of America |
High |
20351249
|
| 2010 |
Skeletal muscle-specific Med1 knockout mice show enhanced insulin sensitivity, improved glucose tolerance, resistance to high-fat diet-induced obesity, increased mitochondrial density, and a fast-to-slow fiber switch with increased expression of UCP-1 and Cidea genes, implicating MED1 as a suppressor of energy expenditure genetic programs in skeletal muscle. |
Tissue-specific conditional knockout, metabolic phenotyping, gene expression profiling |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
20479251
|
| 2011 |
CRPC-specific enhancers drive UBE2C overexpression through MED1 recruitment. PI3K/AKT-phosphorylated MED1 mediates recruitment of FoxA1, RNA polymerase II, and TATA-binding protein to the UBE2C locus, driving long-range enhancer/promoter looping and UBE2C gene expression and cell growth. |
ChIP, chromosome conformation capture (3C), RNAi knockdown, phospho-mutant constructs, cell growth assay |
The EMBO journal |
High |
21556051
|
| 2011 |
MED1 directly interacts with the E2A activation domain and is specifically required for E2A-PBX1-dependent gene activation and leukemic cell growth. RUNX1 recruits E2A-PBX1 to chromatin and this interaction can be stabilized by EBF1. |
Co-immunoprecipitation, CRISPR/Cas9 MED1 depletion, transcriptome and cistrome analysis, in vitro binding assay |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
33542097
|
| 2011 |
ARGLU1 directly interacts with a far C-terminal region of MED1, co-localizes with MED1 in the nucleus, cooperates with MED1 to regulate ER-mediated gene transcription, and is recruited in a ligand-dependent manner to endogenous ER target gene promoters; co-occupancy of ARGLU1 and MED1 on the same ER target gene promoter was confirmed by ChIP-reChIP. |
Co-immunoprecipitation, GST pulldown, ChIP and ChIP-reChIP, reporter assay, RNAi |
The Journal of biological chemistry |
Medium |
21454576
|
| 2011 |
MED1 is a novel cross-talk point for HER2 and ERα pathways. MED1 is phosphorylated by HER2 signaling at a site critical for its activation. Phosphorylated MED1 is recruited to ERα target gene promoters by tamoxifen in HER2-overexpressing cells; RNAi attenuation of MED1 or mutation of its phosphorylation sites restores recruitment of corepressors N-CoR and SMRT. MED1 is also required for HER2 gene expression itself. |
Co-immunoprecipitation, ChIP, RNAi knockdown, phospho-mutant constructs, tissue microarray |
Cancer research |
Medium |
22964581
|
| 2011 |
T cell-specific Med1 deficiency causes a specific block in iNKT cell development but conventional αβ T cell development remains largely normal. The defect is cell-intrinsic and is rescued by ectopic Vα14-Jα18 TCR transgene expression. Thymic iNKT cells in Med1-null animals display reduced IL-2Rβ and T-bet expression. |
T cell-specific conditional knockout, flow cytometry, TCR transgene rescue experiment |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
21949387
|
| 2011 |
Med1-specific conditional knockout in erythroid lineage causes a complete block in erythroid development (absence of β-globin gene expression) but not in myeloid or lymphoid development. Dynamic recruitment of GATA-1, TFIIB, Mediator, and RNA polymerase II to the β-globin locus was demonstrated in induced erythroid cells. |
Med1 conditional knockout mice, ChIP time-course in induced erythroid cells, gene expression analysis |
Proceedings of the National Academy of Sciences of the United States of America |
High |
21098667
|
| 2011 |
MED1 is required for androgen receptor (AR)-mediated transcription through a non-canonical interaction: MED1 binds to the AR N-terminal transactivation unit-1 (Tau-1) via two newly discovered non-canonical α-helical motifs between MED1 residues 505–537, not through its two LXXLL motifs. Loss of the AR N/C intramolecular interaction decreases MED1 binding. MAPK phosphorylation of MED1 enhances the AR–MED1 interaction in prostate cancer cells. |
Co-immunoprecipitation with deletion/point mutants, in vitro binding assay, reporter assay |
The Journal of biological chemistry |
Medium |
22102282
|
| 2012 |
MED1 and MED24 cooperatively contribute to pubertal mammary gland development; MED1/MED24 double heterozygous knockout mice show profound ductal branching retardation during puberty while single haploinsufficient glands develop normally. The cooperation is mediated through ER-dependent regulation of E2F1 and cyclin D1 expression. |
Double heterozygous knockout mouse model, mammary gland histology, gene expression analysis, reporter assay in double-mutant MEFs |
Molecular and cellular biology |
Medium |
22331469
|
| 2013 |
AMP-activated protein kinase (AMPK) directly interacts with Med1 and phosphorylates Med1 in vitro at serine 656, serine 756, and serine 796. AMPK also phosphorylates Med1 in vivo in mouse liver and cultured cells. AMPK inhibition decreases Med1-induced hepatocyte proliferation and PPARα activator-inducible fatty acid β-oxidation in liver. |
In vitro kinase assay with recombinant proteins, in vivo phosphorylation by adenoviral overexpression, AMPK inhibitor compound C, liver-specific overexpression |
The Journal of biological chemistry |
Medium |
23943624
|
| 2014 |
Clk2 (Cdc2-like kinase 2) phosphorylates PGC-1α, which disrupts the interaction between PGC-1α and Mediator subunit MED1, suppressing PGC-1α activation of PPARα target genes in fatty acid oxidation and ketogenesis. |
Co-immunoprecipitation of PGC-1α–MED1 complex, in vitro kinase assay, liver-specific Clk2 knockout, primary hepatocyte manipulation |
Diabetes |
Medium |
24458359
|
| 2015 |
PRDM16 directly interacts with MED1 through its zinc finger domains, is recruited to the Ucp1 enhancer through this interaction, and enhances TR-driven transcription in a biochemically defined system in a Mediator-dependent manner. Cell-based studies confirmed MED1 and TR dependency for PRDM16-induced Ucp1 expression. |
GST pulldown, co-immunoprecipitation, in vitro transcription with purified components, ChIP, RNAi knockdown |
Genes & development |
High |
25644605
|
| 2016 |
cAMP-dependent protein kinase A (PKA) phosphorylates MED1 during human endometrial stromal cell (HESC) decidualization. PKA-phosphorylated MED1 interacts with ESR1 (ERα), and this phosphorylation correlates with enhanced MED1 recruitment to estrogen-responsive elements in the WNT4 gene. MED1 knockdown impairs ESR1-induced WNT4 and FOXO1 expression and blocks decidualization. |
Immunoprecipitation, kinase assay, ChIP, RNAi knockdown in primary HESCs |
Molecular endocrinology (Baltimore, Md.) |
Medium |
26849466
|
| 2019 |
MED1 undergoes CDK7-dependent phosphorylation at T1457 and physically engages AR at superenhancer sites. CDK7 inhibition (THZ1) blocks AR/MED1 co-recruitment genome-wide, reverses the hyperphosphorylated MED1-associated enzalutamide-resistant phenotype, and induces tumor regression of AR-amplified CRPC in a xenograft model. |
ChIP-seq, co-immunoprecipitation, CDK7 inhibitor THZ1, xenograft tumor model, phospho-mutant analysis |
Cancer discovery |
High |
31466944
|
| 2020 |
Structural and biophysical analyses of MED1 interaction with the VDR–RXR heterodimer bound to DNA reveal that ligand-dependent interaction between VDR and the second coactivator motif (LXM2) of MED1 is crucial for complex formation. Additionally, RXR regions interact with the structured N-terminal domain of MED1, and VDR regions outside the classical coactivator binding cleft are affected by coactivator recruitment. |
Structural biology (combination of methods), biophysical binding assays (SEC, native MS), mutational analysis |
Nucleic acids research |
High |
32990725
|
| 2020 |
USP22 interacts with MED1 but does not deubiquitinate MED1 directly. Instead, USP22 enhances MED1 transcriptional activation functions for IL-2Rβ and T-bet gene expression through deubiquitinating histone H2A (not H2B) monoubiquitination, establishing a USP22–histone H2A deubiquitination–MED1 axis in iNKT cell development. |
Co-immunoprecipitation, iNKT-specific conditional knockout, ubiquitination assay, gene expression analysis |
The Journal of experimental medicine |
Medium |
32069354
|
| 2021 |
KDM4B physically and functionally associates with CCAR1 and MED1 in a complex. Genome-wide ChIP-seq shows the KDM4B–CCAR1–MED1 complex is localized to promoters of osteoclast-related genes upon RANKL stimulation; the complex induces euchromatinization through H3K9 demethylation, enabling NF-κB p65 recruitment via direct interaction between KDM4B and p65. |
Co-immunoprecipitation, ChIP-seq, H3K9 methylation assay, conditional knockout mice, small molecule inhibitor |
Bone research |
Medium |
34031372
|
| 2021 |
MED1 is required for postnatal adipose expansion and induction of fatty acid/triglyceride synthesis genes when pups switch from high-fat maternal milk to carbohydrate-based chow. Mechanistically, MED1 facilitates lipogenic transcription factor ChREBP- and SREBP1a-dependent recruitment of Mediator to active enhancers. MED1 is dispensable for adipose development and for PPARγ/C/EBPα induction during adipogenesis. |
Adipose-specific conditional knockout, ChIP for ChREBP/SREBP1a and Mediator, gene expression profiling |
Genes & development |
Medium |
33888555
|
| 2022 |
MED1, when phosphorylated at T1032 by CDK9, dynamically moves with RNA polymerase II throughout transcribed genes to drive Pol II recycling after the initial round of transcription. MED31 mediates the recycling of phosphorylated MED1 and Pol II, enhancing mRNA output. MED1 phosphorylation increases during prostate cancer progression and CDK9 inhibition decreases MED1 phosphorylation and Pol II recycling. |
In vitro and in vivo transcription recycling assays, phospho-mutant analysis, CDK9 inhibitor, prostate cancer progression analysis |
Nucleic acids research |
High |
35394046
|
| 1997 |
RB18A (MED1/TRAP220) interacts in vitro with p53 through its C-terminal domain, binds DNA, self-oligomerizes, and regulates p53 specific binding to its DNA consensus site. RB18A activated the Bax promoter and inhibited p21Waf1 or IGF-BP3 promoters driven by p53 in vivo; RB18A interacts with p53 in vivo. |
Co-immunoprecipitation with p53, in vitro pulldown, transfection reporter assay with p53-responsive promoters |
Oncogene |
Medium |
11118038 9444950
|
| 2004 |
BRCA1's BRCT domain directly interacts with TRAP220 (MED1) in vitro and in vivo; BRCT point mutations found in patients that lack transactivation function abolish this interaction. BRCA1 transactivation function depends on TRAP220 expression levels, and antisense TRAP220 significantly reduces survival of BRCA1-expressing cells after DNA damage. |
GST pulldown, co-immunoprecipitation, transient expression reporter assay, BRCT point mutant analysis, cell survival assay |
Oncogene |
Medium |
15208681
|
| 2010 |
MED1 in bone marrow stromal cells supports hematopoietic stem/progenitor cells through VDR- and Runx2-mediated expression of osteopontin (OPN). Med1-null MEFs show attenuated OPN expression and Mediator recruitment to the Opn promoter; addition of OPN to Med1-null MEF co-cultures restores hematopoietic progenitor growth. |
Med1 knockout MEF co-culture with bone marrow cells, ChIP, gene expression analysis, OPN rescue experiment |
Molecular and cellular biology |
Medium |
20713445
|
| 2018 |
Cardiac-specific Med1 deletion reduces RNA polymerase II occupancy at the majority of transcriptional start sites (increased pausing index) without a corresponding increase in elongating species. Med1-dependent gene expression strongly correlates with H3K27 acetylation at TSS; H3K27me3 levels are broadly increased upon Med1 deletion. Med1 determines chromatin accessibility within genes and at enhancer regions. |
ChIP-seq for Pol II, H3K27ac, H3K27me3 in cardiac Med1 knockout versus floxed control mice |
American journal of physiology. Heart and circulatory physiology |
Medium |
30461303
|
| 2021 |
Med1 controls CD8+ T cell peripheral maintenance through IL-7Rα/STAT5 pathway-mediated cell survival. T cell-specific Med1 deletion reduces CD8+ T cell proportion in spleen in a cell-intrinsic manner (competitive transfer confirmed), with increased cell death, decreased IL-7Rα expression, reduced pSTAT5, and elevated Bim. |
T cell-specific conditional knockout, competitive bone marrow transfer, flow cytometry, gene expression analysis |
Journal of cellular and molecular medicine |
Medium |
33733611
|
| 2022 |
MED1 acts synergistically with KLF4 to transactivate BMPR2, ERG, and TGFBR2 in pulmonary endothelial cells via chromatin remodeling and enhancer-promoter interactions. EC-specific MED1 knockout mice show pulmonary hypertension susceptibility; MED1 overexpression mitigates PH phenotype in rodents. MED1 levels are decreased in lung tissue from idiopathic PAH patients. |
RNA-seq, MED1 ChIP-seq, H3K27ac ChIP-seq, ATAC-seq, Hi-C, endothelial-specific MED1 knockout mice, adenoviral MED1 overexpression |
Circulation research |
High |
36252121
|
| 2022 |
MED1 interacts with SMAD2 and MED1 downregulation protects SMAD2 from ubiquitination-dependent degradation, thereby enhancing TGFβ/SMAD2 signaling, epithelial-to-mesenchymal transition, and metastasis in cutaneous melanoma. |
Co-immunoprecipitation, ubiquitination assay, RNAi knockdown, in vivo xenograft metastasis model |
The Journal of investigative dermatology |
Medium |
35131256
|