MED18

gene
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Also known as FLJ20045p28bSRB5

Summary

MED18 (mediator complex subunit 18, HGNC:25944) is a protein-coding gene on chromosome 1p35.3, encoding Mediator of RNA polymerase II transcription subunit 18 (Q9BUE0). Component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. It is a selective cancer dependency (DepMap: 89.4% of cell lines).

MED18 is a component of the Mediator complex, which is a coactivator for DNA-binding factors that activate transcription via RNA polymerase II (Sato et al., 2003 [PubMed 12584197]).

Source: NCBI Gene 54797 — RefSeq curated summary.

At a glance

  • GWAS associations: 1
  • Clinical variants (ClinVar): 33 total
  • Cancer dependency (DepMap): dependent in 89.4% of screened cell lines
  • MANE Select transcript: NM_017638

Identifiers

Gene identifiers

FieldValue
HGNC IDHGNC:25944
Approved symbolMED18
Namemediator complex subunit 18
Location1p35.3
Locus typegene with protein product
StatusApproved
AliasesFLJ20045, p28b, SRB5
Ensembl geneENSG00000130772
Ensembl biotypeprotein_coding
OMIM612384
Entrez54797

Gene structure

Transcript identifiers

Ensembl transcripts: 5 — 3 protein_coding_CDS_not_defined, 2 protein_coding

ENST00000373842, ENST00000398997, ENST00000474683, ENST00000475655, ENST00000479574

RefSeq mRNA: 2 — MANE Select: NM_017638 NM_001127350, NM_017638

CCDS: CCDS322

Canonical transcript exons

ENST00000373842 — 3 exons

ExonStartEnd
ENSE000012079492832904028329180
ENSE000018661532833441728335965
ENSE000035574172833059728330735

Expression profiles

Bgee: expression breadth ubiquitous, 134 present calls, max score 87.11.

FANTOM5 (CAGE): breadth ubiquitous, TPM avg 10.6066 / max 94.0650, expressed in 1783 samples.

FANTOM5 promoters (1 alternative TSS)

Promoter IDTPM avgSamples expressed
178910.60661783

Top tissues by expression

134 total, by Bgee expression score (0-100, higher = more expressed):

TissueAnatomy IDExpression scoreQuality
mucosa of transverse colonUBERON:000499187.11gold quality
islet of LangerhansUBERON:000000686.77gold quality
stromal cell of endometriumCL:000225585.41gold quality
lymph nodeUBERON:000002984.16gold quality
bloodUBERON:000017884.00gold quality
rectumUBERON:000105283.87gold quality
granulocyteCL:000009482.84gold quality
skeletal muscle tissueUBERON:000113482.72gold quality
duodenumUBERON:000211482.64gold quality
muscle tissueUBERON:000238582.43gold quality
vermiform appendixUBERON:000115482.00gold quality
liverUBERON:000210781.90gold quality
hindlimb stylopod muscleUBERON:000425281.88gold quality
leukocyteCL:000073881.87gold quality
male germ line stem cell (sensu Vertebrata) in testisCL:0000089 ∩ UBERON:000047381.75gold quality
monocyteCL:000057681.56gold quality
muscle of legUBERON:000138381.52gold quality
gastrocnemiusUBERON:000138881.32gold quality
placentaUBERON:000198781.14gold quality
transverse colonUBERON:000115780.83gold quality
tonsilUBERON:000237280.77gold quality
right adrenal glandUBERON:000123380.73gold quality
right adrenal gland cortexUBERON:003582780.65gold quality
right lobe of liverUBERON:000111480.58gold quality
smooth muscle tissueUBERON:000113580.32gold quality
esophagus mucosaUBERON:000246980.12gold quality
small intestineUBERON:000210880.04gold quality
pancreasUBERON:000126479.87gold quality
small intestine Peyer’s patchUBERON:000345479.72gold quality
bone marrowUBERON:000237179.53gold quality

Single-cell (SCXA)

Detected in 1 experiment(s), a significant marker in 0.

ExperimentMarker?Max mean expression
E-ANND-3no1.65

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

49 targeting MED18, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):

miRNAMax scoreAvg scoremiRNA target_count
HSA-MIR-1252-5P100.0069.802774
HSA-MIR-371B-5P99.9975.344759
HSA-MIR-4789-5P99.9870.762721
HSA-MIR-373-5P99.9875.364753
HSA-MIR-616-5P99.9875.584775
HSA-MIR-1229-3P99.9766.49906
HSA-MIR-548AA99.9670.643753
HSA-MIR-548AP-3P99.9670.643753
HSA-MIR-548T-3P99.9670.643753
HSA-MIR-6778-3P99.9667.292693
HSA-MIR-153-5P99.8973.866317
HSA-MIR-6780A-5P99.8866.692776
HSA-MIR-221-5P99.8665.451052
HSA-MIR-807399.8665.211118
HSA-MIR-6515-3P99.8268.191933
HSA-MIR-556-3P99.7468.751203
HSA-MIR-674599.7465.331321
HSA-MIR-613499.6365.681537
HSA-MIR-766-3P99.4765.241811
HSA-MIR-504-3P99.3067.181745
HSA-MIR-478499.1567.411733
HSA-MIR-66199.0965.942062
HSA-MIR-4695-5P99.0664.871151
HSA-MIR-392698.9569.261438
HSA-MIR-3150B-3P98.8167.211728
HSA-MIR-7113-3P98.7565.711120
HSA-MIR-4763-5P98.7563.89854
HSA-MIR-548S98.5067.171213
HSA-MIR-6878-5P98.4967.912142
HSA-MIR-5089-5P98.4566.061388

Functional genomics

DepMap (CRISPR cell-line fitness): dependent in 89.4% of screened cell lines.

Literature-anchored findings (GeneRIF, showing 2)

  • A novel transcriptional repression mechanism of hMED18 mediated by hCDK8 and further a novel positive role of free CDK/cyclin module in transcriptional activation is described. (PMID:24840924)
  • Long non-coding RNA SNHG3 promotes progression of gastric cancer by regulating neighboring MED18 gene methylation. (PMID:31534128)

Cross-species orthologs

5 orthologs

OrganismSymbolGene ID
danio_reriomed18ENSDARG00000041237
mus_musculusMed18ENSMUSG00000066042
rattus_norvegicusMed18ENSRNOG00000067073
drosophila_melanogasterMED18FBGN0026873
caenorhabditis_elegansmdt-18WBGENE00007018

Protein

Protein identifiers

Mediator of RNA polymerase II transcription subunit 18Q9BUE0 (reviewed: Q9BUE0)

Alternative names: Mediator complex subunit 18, p28b

All UniProt accessions (1): Q9BUE0

UniProt curated annotations — full annotation on UniProt →

Function. Component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. Mediator is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors.

Subunit / interactions. Component of the Mediator complex, which is composed of MED1, MED4, MED6, MED7, MED8, MED9, MED10, MED11, MED12, MED13, MED13L, MED14, MED15, MED16, MED17, MED18, MED19, MED20, MED21, MED22, MED23, MED24, MED25, MED26, MED27, MED29, MED30, MED31, CCNC, CDK8 and CDC2L6/CDK11. The MED12, MED13, CCNC and CDK8 subunits form a distinct module termed the CDK8 module. Mediator containing the CDK8 module is less active than Mediator lacking this module in supporting transcriptional activation. Individual preparations of the Mediator complex lacking one or more distinct subunits have been variously termed ARC, CRSP, DRIP, PC2, SMCC and TRAP.

Subcellular location. Nucleus.

Similarity. Belongs to the Mediator complex subunit 18 family.

RefSeq proteins (2): NP_001120822, NP_060108* (*=MANE)

Domains & families (InterPro)

IDNameType
IPR019095Mediator_Med18Family

Pfam: PF09637

UniProt features (17 total): strand 10, helix 3, chain 1, modified residue 1, turn 1, sequence conflict 1

Structure

Experimental structures (PDB)

11 structures.

PDBMethodResolution (Å)
7EMFELECTRON MICROSCOPY3.5
8TRHELECTRON MICROSCOPY3.7
7ENAELECTRON MICROSCOPY4.07
7ENCELECTRON MICROSCOPY4.13
8GXSELECTRON MICROSCOPY4.16
7ENJELECTRON MICROSCOPY4.4
7NVRELECTRON MICROSCOPY4.5
8T9DELECTRON MICROSCOPY4.66
7LBMELECTRON MICROSCOPY4.8
8GXQELECTRON MICROSCOPY5.04
8TQWELECTRON MICROSCOPY8.2

Predicted structure (AlphaFold)

ModelpLDDTFraction very-high
AF-Q9BUE0-F190.120.78

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Post-translational modifications (1): 66

Function

Pathways and Gene Ontology

Reactome pathways

12 pathways

IDPathway
R-HSA-1989781PPARA activates gene expression
R-HSA-381340Transcriptional regulation of white adipocyte differentiation
R-HSA-9833110RSV-host interactions
R-HSA-1266738Developmental Biology
R-HSA-1430728Metabolism
R-HSA-1643685Disease
R-HSA-400206Regulation of lipid metabolism by PPARalpha
R-HSA-556833Metabolism of lipids
R-HSA-5663205Infectious disease
R-HSA-9820952Respiratory Syncytial Virus Infection Pathway
R-HSA-9824446Viral Infection Pathways
R-HSA-9843745Adipogenesis

MSigDB gene sets: 119 (showing top): REACTOME_TRANSCRIPTIONAL_REGULATION_OF_WHITE_ADIPOCYTE_DIFFERENTIATION, GOBP_POSITIVE_REGULATION_OF_DNA_TEMPLATED_TRANSCRIPTION_INITIATION, MODULE_205, GOBP_REGULATION_OF_DNA_TEMPLATED_TRANSCRIPTION_INITIATION, TAKEDA_TARGETS_OF_NUP98_HOXA9_FUSION_10D_UP, GOBP_DNA_TEMPLATED_TRANSCRIPTION_INITIATION, GOBP_TRANSCRIPTION_INITIATION_AT_RNA_POLYMERASE_II_PROMOTER, LASTOWSKA_NEUROBLASTOMA_COPY_NUMBER_DN, GOBP_PROTEIN_DNA_COMPLEX_ORGANIZATION, GOBP_POSITIVE_REGULATION_OF_DNA_TEMPLATED_TRANSCRIPTION_ELONGATION, GOBP_REGULATION_OF_DNA_TEMPLATED_TRANSCRIPTION_ELONGATION, PARENT_MTOR_SIGNALING_UP, GOCC_RNA_POLYMERASE_II_TRANSCRIPTION_REGULATOR_COMPLEX, GOCC_TRANSCRIPTION_REGULATOR_COMPLEX, MARSON_BOUND_BY_E2F4_UNSTIMULATED

GO Biological Process (4): positive regulation of transcription elongation by RNA polymerase II (GO:0032968), RNA polymerase II preinitiation complex assembly (GO:0051123), positive regulation of transcription initiation by RNA polymerase II (GO:0060261), regulation of transcription by RNA polymerase II (GO:0006357)

GO Molecular Function (2): transcription coregulator activity (GO:0003712), protein binding (GO:0005515)

GO Cellular Component (4): nucleus (GO:0005634), nucleoplasm (GO:0005654), mediator complex (GO:0016592), core mediator complex (GO:0070847)

Reactome top-level categories

Rollup of top-9 pathways:

CategoryPathways
Regulation of lipid metabolism by PPARalpha1
Adipogenesis1
Respiratory Syncytial Virus Infection Pathway1
Metabolism of lipids1
Metabolism1
Disease1
Viral Infection Pathways1
Infectious disease1
Developmental Biology1

GO top-level categories

Rollup of top GO terms by namespace:

CategoryTerms
positive regulation of transcription by RNA polymerase II2
transcription initiation at RNA polymerase II promoter2
transcription elongation by RNA polymerase II1
positive regulation of DNA-templated transcription, elongation1
regulation of transcription elongation by RNA polymerase II1
transcription preinitiation complex assembly1
regulation of transcription initiation by RNA polymerase II1
positive regulation of DNA-templated transcription initiation1
regulation of DNA-templated transcription1
transcription by RNA polymerase II1
transcription regulator activity1
binding1
intracellular membrane-bounded organelle1
nuclear lumen1
cellular anatomical structure1
core mediator complex1
nuclear protein-containing complex1
RNA polymerase II transcription regulator complex1

Protein interactions and networks

STRING

1064 interactions, top by confidence (×1000):

Protein AProtein BPartner UniProtScore
MED18MED20Q9H944999
MED18MED11Q9P086998
MED18MED8Q96G25996
MED18MED6O75586995
MED18MED22Q15528991
MED18MED29Q9NX70979
MED18MED19A0JLT2977
MED18MED10Q9BTT4959
MED18MED17Q9NVC6950
MED18MED30Q96HR3931
MED18MED14O60244931
MED18CDK8P49336913
MED18MED16Q9Y2X0888
MED18MED15Q96RN5884
MED18MED21Q13503873

IntAct

150 interactions, top by confidence:

ABTypeScore
MED20MED18psi-mi:“MI:0915”(physical association)0.960
MED18MED20psi-mi:“MI:0915”(physical association)0.960
MED10MED19psi-mi:“MI:0914”(association)0.910
MED10MED19psi-mi:“MI:0915”(physical association)0.910
MED4MED19psi-mi:“MI:2364”(proximity)0.900
MED4MED19psi-mi:“MI:0914”(association)0.900
MED29MED19psi-mi:“MI:0914”(association)0.890
MED29MED18psi-mi:“MI:0914”(association)0.890
MED29MED18psi-mi:“MI:0915”(physical association)0.890
MED21MED19psi-mi:“MI:0914”(association)0.880

BioGRID (289): MED18 (Two-hybrid), MED18 (Two-hybrid), TRIM39 (Two-hybrid), HOMEZ (Two-hybrid), MED18 (Affinity Capture-MS), MED18 (Affinity Capture-MS), MED18 (Affinity Capture-MS), MED1 (Co-fractionation), MED11 (Co-fractionation), MED12 (Co-fractionation), MED14 (Co-fractionation), MED15 (Co-fractionation), MED16 (Co-fractionation), MED17 (Co-fractionation), MED18 (Co-fractionation)

ESM2 similar proteins: A1CE73, A1CGW7, A1CLT5, A1CQ63, A1D327, A1DM82, A2Q9L8, A2RBB7, A4D9J5, A4RI88, G0RYC6, G0S0E7, G0S8H7, G0S9A7, O14198, P34162, P91641, Q0CL68, Q0VCD4, Q17IN5, Q1E065, Q28GE1, Q2H4N1, Q2KG01, Q2UMB8, Q4WNC6, Q54MR3, Q5B128, Q5BE03, Q5KEQ1, Q61D43, Q6BXL9, Q6CAY6, Q6CDK1, Q6DD39, Q6DRD4, Q6FSU0, Q755F7, Q75EI4, Q7QGX9

Diamond homologs: Q0VCD4, Q17IN5, Q28GE1, Q6DD39, Q7QGX9, Q7T3H7, Q966M5, Q9BUE0, Q9CZ82, Q9XZT1, Q61D43

SIGNOR signaling

1 interactions.

AEffectBMechanism
MED18“form complex”“Core mediator complex”binding

Enriched among interaction partners

Reactome pathways and GO biological processes over-represented among this gene’s 68 IntAct physical interaction partners (hypergeometric vs the genome-wide background, BH-FDR, gene-set size 15–500, ranked by fold). A functional readout of the neighbourhood — distinct from this gene’s own memberships above, and biased toward well-studied / hub proteins, so read it as themes rather than proof.

Reactome pathways:

PathwayPartnersFoldFDR
Respiratory Syncytial Virus Infection Pathway2598.5×5e-44
RSV-host interactions2578.2×2e-41
Adipogenesis2578.2×2e-41
Regulation of lipid metabolism by PPARalpha2570.5×4e-40
Epigenetic regulation of adipogenesis genes by MLL3 and MLL4 complexes1669.0×8e-25
Transcriptional regulation of white adipocyte differentiation2564.9×3e-39
Epigenetic regulation of gene expression by MLL3 and MLL4 complexes1663.0×3e-24
Epigenetic regulation by WDR5-containing histone modifying complexes1649.4×2e-22

GO biological processes:

GO termPartnersFoldFDR
positive regulation of transcription elongation by RNA polymerase II21107.1×1e-36
positive regulation of transcription initiation by RNA polymerase II22101.3×1e-37
RNA polymerase II preinitiation complex assembly2196.7×9e-36
transcription initiation at RNA polymerase II promoter850.8×2e-10
somatic stem cell population maintenance1146.2×4e-14
protein ubiquitination128.4×8e-07
transcription by RNA polymerase II78.4×7e-04

Disease & clinical

Clinical variants and AI predictions

ClinVar

33 variants total. Per-class counts are floors (≥ shown; pagination cap):

ClassificationCount (floor)
Pathogenic0
Likely pathogenic0
Uncertain significance30
Likely benign1
Benign0

Top pathogenic / likely-pathogenic (0)

SpliceAI

290 predictions. Top by Δscore:

VariantEffectΔscore
1:28329178:G:GTdonor_gain1.0000
1:28330591:TTCCA:Tacceptor_loss1.0000
1:28330592:TCCA:Tacceptor_loss1.0000
1:28330593:CCA:Cacceptor_loss1.0000
1:28330594:CA:Cacceptor_loss1.0000
1:28330595:AGGTA:Aacceptor_loss1.0000
1:28330596:G:GAacceptor_loss1.0000
1:28330731:GCAGG:Gdonor_gain1.0000
1:28330732:CAGG:Cdonor_gain1.0000
1:28330732:CAGGG:Cdonor_loss1.0000
1:28330734:GG:Gdonor_gain1.0000
1:28330735:GG:Gdonor_gain1.0000
1:28330736:G:GGdonor_gain1.0000
1:28330736:GTA:Gdonor_loss1.0000
1:28330737:T:Adonor_loss1.0000
1:28334416:GGA:Gacceptor_gain1.0000
1:28334416:GGAA:Gacceptor_gain1.0000
1:28329177:GGAG:Gdonor_gain0.9900
1:28329178:G:Tdonor_gain0.9900
1:28329232:G:GTdonor_gain0.9900
1:28330596:GGT:Gacceptor_gain0.9900
1:28330596:GGTAT:Gacceptor_gain0.9900
1:28330719:G:GTdonor_gain0.9900
1:28330733:AGG:Adonor_gain0.9900
1:28330734:GGG:Gdonor_gain0.9900
1:28334412:TTCA:Tacceptor_loss0.9900
1:28334415:A:AGacceptor_gain0.9900
1:28334415:AG:Aacceptor_gain0.9900
1:28334416:G:GGacceptor_gain0.9900
1:28334416:GG:Gacceptor_gain0.9900

AlphaMissense

1400 scored. Top likely-pathogenic:

VariantProtein changeam_pathogenicity
1:28330735:G:AG25R1.000
1:28330735:G:CG25R1.000
1:28334459:T:CL39P1.000
1:28334921:T:CL193P1.000
1:28334417:G:AG25E0.999
1:28334423:T:AV27D0.999
1:28334455:C:AR38S0.999
1:28334459:T:AL39H0.999
1:28334464:G:CG41R0.999
1:28334465:G:AG41D0.999
1:28334471:G:AC43Y0.999
1:28334597:T:CL85P0.999
1:28334600:G:CR86P0.999
1:28334602:T:GY87D0.999
1:28334651:G:CR103P0.999
1:28334740:G:AG133R0.999
1:28334740:G:CG133R0.999
1:28334741:G:AG133E0.999
1:28334933:T:AV197D0.999
1:28334447:T:CL35P0.998
1:28334456:G:CR38P0.998
1:28334459:T:GL39R0.998
1:28334472:T:GC43W0.998
1:28334558:C:AA72D0.998
1:28334609:G:AG89E0.998
1:28334696:T:CL118S0.998
1:28334710:T:CF123L0.998
1:28334711:T:CF123S0.998
1:28334712:C:AF123L0.998
1:28334712:C:GF123L0.998

dbSNP variants (sampled 300 via entrez): RS1000090415 (1:28335913 T>A), RS1000273693 (1:28331028 T>C), RS1001191827 (1:28329992 G>A,C), RS1001328743 (1:28330236 T>C), RS1001339585 (1:28336375 T>C), RS1001623422 (1:28330198 C>T), RS1001931813 (1:28331749 ATT>A,AT,ATTT,ATTTT), RS1002221418 (1:28328995 G>A,C), RS1002342080 (1:28335273 C>G), RS1002374693 (1:28335499 C>G,T), RS1002596809 (1:28328837 C>G), RS1003209061 (1:28327509 C>A,G), RS1003347317 (1:28333628 G>A), RS1003397827 (1:28333726 G>C), RS1003649575 (1:28327831 C>T)

Disease associations

OMIM: gene MIM:612384 | disease phenotypes:

GenCC curated gene-disease

Mondo (0):

Orphanet (0):

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

1 associations (top):

StudyTraitp-value
GCST004250_24Alanine aminotransferase (ALT) levels after remission induction therapy in actute lymphoblastic leukemia (ALL)3.000000e-06

EFO canonical traits (1, from GWAS)

EFO IDTrait name
EFO:0007965response to combination chemotherapy

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

CTD chemical–gene interactions

29 total (human), top 29 by PubMed support.

ChemicalActions (top 5)PubMed papers
sodium arseniteincreases abundance, increases expression, increases stability, decreases expression5
Arsenicincreases abundance, increases methylation, decreases expression2
Benzo(a)pyreneaffects methylation, increases expression2
3-((6-(2-methoxyphenyl)pyrimidin-4-yl)amino)phenyl)methane sulfonamidedecreases expression1
bisphenol Fincreases expression, affects cotreatment1
urushioldecreases expression1
bisphenol Aaffects cotreatment, increases expression1
ferrous chloridedecreases expression1
di-n-butylphosphoric acidaffects expression1
corosolic acidincreases expression1
monomethylarsonous aciddecreases expression1
bisphenol Saffects cotreatment, increases expression1
Dexamethasoneaffects cotreatment, increases expression1
Diethylhexyl Phthalateincreases expression1
Estradiolaffects expression1
Indomethacinaffects cotreatment, increases expression1
Rotenonedecreases expression1
Silicon Dioxidedecreases expression1
Dronabinoldecreases expression1
Thimerosaldecreases expression1
Thiramdecreases expression1
Tretinoinincreases expression1
Urethaneincreases expression1
1-Methyl-3-isobutylxanthineaffects cotreatment, increases expression1
7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxidedecreases expression1
Metriboloneaffects splicing1
Cadmium Chloridedecreases expression1
Lactic Aciddecreases expression1
Acrylamideincreases expression1

Clinical trials (associated diseases)

0 trials via MONDO — disease-level, not drug-specific.

No linked Atlas pages yet — the cross-entity mesh grows as the corpus expands.