FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\MED31
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General Information
Symbol
Dmel\MED31
Species
D. melanogaster
Name
Mediator complex subunit 31
Annotation Symbol
CG1057
Feature Type
protein_coding_gene
FlyBase ID
FBgn0037262
Gene Model Status
Current
Stock Availability
7 publicly available
Gene Summary
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. Required for activated transcription of the MtnA gene. (UniProt, Q8IH24)
Contribute a Gene Snapshot for this gene.
All Summaries
Also Known As

Trap18, dSOH1

Key Links
Genomic Location
Cytogenetic map
82C5-82C5
Sequence location
Recombination map
3-47.1
RefSeq locus
NT_033777 REGION:4641963..4643292
Sequence
Get Decorated FASTA
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
NCBI
UCSC
Ensembl
PopFly
Function
Gene Ontology (GO) Annotations (9 terms)
Molecular Function (3 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
enables protein binding
inferred from physical interaction with UniProtKB:Q8MSX2
(Park et al., 2001)
inferred from physical interaction with UniProtKB:Q9VS38
(Gu et al., 2002)
contributes_to transcription coactivator activity
inferred from direct assay
(Gu et al., 2002)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
enables transcription coregulator activity
inferred from electronic annotation with InterPro:IPR008831
(InterPro Project Members, 2004-)
Biological Process (3 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
involved_in anterior/posterior axis specification, embryo
inferred from mutant phenotype
(Bosveld et al., 2008)
involved_in regulation of transcription by RNA polymerase II
inferred from direct assay
(Gu et al., 2002)
inferred from direct assay
(Park et al., 2001)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
involved_in regulation of DNA-templated transcription
inferred from electronic annotation with InterPro:IPR008831
(InterPro Project Members, 2004-)
involved_in regulation of transcription by RNA polymerase II
inferred from biological aspect of ancestor with PANTHER:PTN000323967
(GO Reference Genome Project, 2011-)
Cellular Component (3 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
part_of mediator complex
inferred from direct assay
(Park et al., 2001)
inferred from direct assay
(Gu et al., 2002)
located_in nucleus
inferred from direct assay
(Park et al., 2003, Gu et al., 2002)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
part_of core mediator complex
inferred from biological aspect of ancestor with PANTHER:PTN000323967
(GO Reference Genome Project, 2011-)
part_of mediator complex
inferred from electronic annotation with InterPro:IPR008831
(InterPro Project Members, 2004-)
inferred from biological aspect of ancestor with PANTHER:PTN000323967
(GO Reference Genome Project, 2011-)
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the Mediator complex subunit 31 family. (Q8IH24)
Protein Signatures (InterPro)
Summaries
Gene Group (FlyBase)
MEDIATOR CORE COMPLEX -
he Mediator (MED) complex serves as a hub for transcriptional signaling events, bridging transcriptional activators and repressors. This large multi-protein complex has a central core conserved from yeast to humans. The core is composed of three modules: head, middle, and tail. (Adapted from FBrf0226415 and FBrf0191850).
Protein Function (UniProtKB)
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. Required for activated transcription of the MtnA gene.
(UniProt, Q8IH24)
Gene Model and Products
Number of Transcripts
5
Number of Unique Polypeptides
3

Please see the JBrowse view of Dmel\MED31 for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)
Isoform displayed:
Pfam protein domains
InterPro name
classification
start
end
Protein Domains (via SMART)
Isoform displayed:
SMART protein domains
InterPro name
classification
start
end
Structure
Protein 3D structure   (Predicted by AlphaFold)   (AlphaFold entry Q8IH24)

If you don't see a structure in the viewer, refresh your browser.
Model Confidence:
  • Very high (pLDDT > 90)
  • Confident (90 > pLDDT > 70)
  • Low (70 > pLDDT > 50)
  • Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures
Crossreferences
Comments on Gene Model

Gene model reviewed during 5.47

Shares 5' UTR with downstream gene.

Low-frequency RNA-Seq exon junction(s) not annotated.

Gene model reviewed during 5.55

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
MED31-RA
FBtr0078856
NM_141226
1098
204
MED31-RB
FBtr0078857
NM_169013
823
204
MED31-RC
FBtr0305312
NM_001259979
818
204
MED31-RD
FBtr0336456
NM_001275329
1092
202
MED31-RE
FBtr0345249
NM_001300230
678
199
Additional Transcript Data and Comments
Reported size (kB)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
MED31-PA
FBpp0078496
23.5
204
7.91
Q8IH24
NP_649483
AAF52111
MED31-PB
FBpp0078497
23.5
204
7.91
Q8IH24
NP_730861
AAN13286
MED31-PC
FBpp0293855
23.5
204
7.91
Q8IH24
NP_001246908
AFH06227
MED31-PD
FBpp0307562
23.3
202
7.28
A0A0B4KG28
NP_001262258
AGB95641
MED31-PE
FBpp0311426
23.0
199
5.78
A0A0B4LGM8
NP_001287159
AHN57158
Polypeptides with Identical Sequences

The group(s) of polypeptides indicated below share identical sequence to each other.

204 aa isoforms: MED31-PA, MED31-PB, MED31-PC
Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Subunit Structure (UniProtKB)

Component of the Mediator complex, which includes at least MED4, MED6, MED14, MED17, MED18, MED20, MED21, MED23, MED24, MED27, MED30 and MED31.

(UniProt, Q8IH24)
Crossreferences
InterPro - A database of protein families, domains and functional sites
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\MED31 using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Expression Data
Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

1.82

Transcript Expression
Polypeptide Expression
western blot
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage
organism
• nucleus
(Gim et al., 2001)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
part_of mediator complex
inferred from direct assay
(Park et al., 2001)
inferred from direct assay
(Gu et al., 2002)
located_in nucleus
inferred from direct assay
(Park et al., 2003, Gu et al., 2002)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\MED31 in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Bulk Downloads
RNA-Seq RPKM values for all genes
Reference
See Gelbart and Emmert, 2013 for analysis details and data files for all genes.
Developmental Proteome: Life Cycle
Developmental Proteome: Embryogenesis
External Data and Images
Linkouts
BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
FlyExpress - Embryonic expression images (BDGP data)
  • Stages(s) 1-3
  • Stages(s) 4-6
  • Stages(s) 7-8
  • Stages(s) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 3 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 8 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of MED31
Transgenic constructs containing regulatory region of MED31
Aberrations (Deficiencies and Duplications) ( 3 )
Inferred from experimentation ( 3 )
Gene not disrupted in
Df(3R)rpk-Karyβ3
(Tsubouchi et al., 2012)
Dp(3;3)HKK2
(Andersen et al., 2011)
Gene disrupted in
Df(3R)Z1
(Bosveld et al., 2008)
Inferred from location ( 8 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
Orthologs
Downloads
Download All DIOPT Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (1)
Hsap\MED31
11 of 14
Yes
Yes
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (1)
Rnor\Med31
11 of 14
Yes
Yes
Mus musculus (laboratory mouse) (1)
Mmus\Med31
10 of 14
Yes
Yes
Xenopus tropicalis (Western clawed frog) (2)
Xtro\med31
8 of 13
Yes
Yes
Xtro\cfap161
1 of 13
No
No
Danio rerio (Zebrafish) (1)
Drer\med31
11 of 14
Yes
Yes
Caenorhabditis elegans (Nematode, roundworm) (1)
Cele\mdt-31
10 of 14
Yes
Yes
Anopheles gambiae (African malaria mosquito) (1)
Agam\AgaP_AGAP002258
9 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (1)
Atha\MED31
10 of 13
Yes
Yes
Saccharomyces cerevisiae (Brewer's yeast) (1)
Scer\SOH1
9 of 13
Yes
Yes
Schizosaccharomyces pombe (Fission yeast) (1)
Spom\med31
9 of 12
Yes
Yes
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:MED31. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 0 )
    Human Ortholog
    Disease
    Evidence
    References
    Modifiers Based on Experimental Evidence ( 1 )
    Allele
    Disease
    Interaction
    References
    MED31HMS01048
    ameliorates  amyotrophic lateral sclerosis type 10
    modeled by Hsap\TARDBPM.UAS.Tag:FLAG
    (Azpurua et al., 2021)
    Disease Associations of Human Orthologs (via DIOPT v9.1 and OMIM)
    Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
    Homo sapiens (Human)
    Gene name
    Score
    OMIM
    OMIM Phenotype
    DO term
    Complementation?
    Transgene?
    MED31; mediator complex subunit 31
    11 of 14
    620492
        Functional Complementation Data
        Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.
        Interactions
        Summary of Physical Interactions
        Summary of Genetic Interactions
        Interaction Browsers
        View in FlyBase Interactions Browser   View in MIST tool (external link)
        Please look at the allele data for full details of the genetic interactions
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        MED31
        enhanceable
        skd
        (Bosveld et al., 2008)
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        External Data
        Subunit Structure (UniProtKB)
        Component of the Mediator complex, which includes at least MED4, MED6, MED14, MED17, MED18, MED20, MED21, MED23, MED24, MED27, MED30 and MED31.
        (UniProt, Q8IH24 )
        Linkouts
        BioGRID - A database of protein and genetic interactions.
        DroID - A comprehensive database of gene and protein interactions.
        MIST (protein-protein) - An integrated Molecular Interaction Database
        Pathways
        Signaling Pathways (FlyBase)
        Metabolic Pathways
        FlyBase
        External Links
        External Data
        Linkouts
        Class of Gene
        Genomic Location and Detailed Mapping Data
        Chromosome (arm)
        3R
        Recombination map
        3-47.1
        Cytogenetic map
        82C5-82C5
        Sequence location
        FlyBase Computed Cytological Location
        Cytogenetic map
        Evidence for location
        82C5-82C5
        Limits computationally determined from genome sequence between P{PZ}l(3)0273302733 and P{EP}EP974
        Experimentally Determined Cytological Location
        Cytogenetic map
        Notes
        References
        Experimentally Determined Recombination Data
        Location

        3-47.1

        (FlyBase, 2016)

        3-44.1

        (Comeron et al., 2012)
        Left of (cM)
        Right of (cM)
        Notes
        Stocks and Reagents
        Stocks (7)
        Genomic Clones (10)
         

        Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete

        cDNA Clones (42)
         

        Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see JBrowse for alignment of the cDNAs and ESTs to the gene model.

        cDNA clones, fully sequenced
        BDGP DGC clones
        Other clones
          Drosophila Genomics Resource Center cDNA clones

          For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

          cDNA Clones, End Sequenced (ESTs)
          BDGP DGC clones
          Other clones
          RNAi and Array Information
          Linkouts
          DRSC - Results frm RNAi screens
          Antibody Information
          Laboratory Generated Antibodies
           
          Commercially Available Antibodies
           
          Cell Line Information
          Publicly Available Cell Lines
           
            Other Stable Cell Lines
             
              Other Comments

              DNA-protein interactions: genome-wide binding profile assayed for MED31 protein in Kc167 cells; see Chromatin_types_NKI collection report. Individual protein-binding experiments listed under "Samples" at GEO_GSE22069 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE22069).

              (Filion et al., 2010)

              dsRNA has been made from templates generated with primers directed against this gene.

              (Marr et al., 2006)
              Relationship to Other Genes
              Source for database merge of

              Source for merge of: Trap18 BcDNA:GM28912

              (FlyBase, 1996-)
              Additional comments

              Source for merge of Trap18 BcDNA:GM28912 was a shared cDNA ( date:030728 ).

              (FlyBase, 1996-)
              Nomenclature History
              Source for database identify of

              Source for identity of: Trap18 CG1057

              (Boube et al., 2000)

              Source for identity of: MED31 Trap18

              (Bourbon et al., 2004)
              Nomenclature comments
              Etymology
              Synonyms and Secondary IDs (11)
              Datasets (1)
              Study focus (1)
              Experimental Role
              Project
              Project Type
              Title
              • transgene_used
              FBGSE22069
              Protein profiling reveals five principal chromatin types in Drosophila cells.
              Study result (0)
              Result
              Result Type
              Title
              External Crossreferences and Linkouts ( 49 )
              Sequence Crossreferences
              NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.
              GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
              GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.
              RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.
              UniProt/GCRP - The gene-centric reference proteome (GCRP) provides a 1:1 mapping between genes and UniProt accessions in which a single 'canonical' isoform represents the product(s) of each protein-coding gene.
              UniProt/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
              UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
              Other crossreferences
              AlphaFold DB - AlphaFold provides open access to protein structure predictions for the human proteome and other key proteins of interest, to accelerate scientific research.
              BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
              DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
              EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
              FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
              FlyMine - An integrated database for Drosophila genomics
              InterPro - A database of protein families, domains and functional sites
              KEGG Genes - Molecular building blocks of life in the genomic space.
              MARRVEL_MODEL - MARRVEL (model organism gene)
              Linkouts
              BioGRID - A database of protein and genetic interactions.
              Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
              DroID - A comprehensive database of gene and protein interactions.
              DRSC - Results frm RNAi screens
              Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
              FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
              FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
              Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
              Flygut - An atlas of the Drosophila adult midgut
              iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
              MIST (protein-protein) - An integrated Molecular Interaction Database
              References (55)