FB2024_02 , released April 23, 2024
Gene: Dmel\exu
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General Information
Symbol
Dmel\exu
Species
D. melanogaster
Name
exuperantia
Annotation Symbol
CG8994
Feature Type
FlyBase ID
FBgn0000615
Gene Model Status
Stock Availability
Gene Summary
Ensures the proper localization of the mRNA of the bicoid gene to the anterior regions of the oocyte thus playing a fundamental role in the establishment of the polarity of the oocyte. May bind the bcd mRNA. (UniProt, P28750)
Contribute a Gene Snapshot for this gene.
Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
2-91
RefSeq locus
NT_033778 REGION:20667427..20671083
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (17 terms)
Molecular Function (5 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
inferred from physical interaction with UniProtKB:P23128
inferred from direct assay
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
enables RNA binding
inferred from electronic annotation with InterPro:IPR037998
inferred from key residues
Biological Process (8 terms)
Terms Based on Experimental Evidence (4 terms)
CV Term
Evidence
References
inferred from expression pattern
inferred from mutant phenotype
inferred from mutant phenotype
inferred from high throughput mutant phenotype
Terms Based on Predictions or Assertions (5 terms)
CV Term
Evidence
References
Cellular Component (4 terms)
Terms Based on Experimental Evidence (4 terms)
CV Term
Evidence
References
inferred from direct assay
located_in cytoplasm
located_in P-body
inferred from direct assay
inferred from high throughput direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
located_in cytoplasm
traceable author statement
Gene Group (FlyBase)
Protein Family (UniProt)
-
Summaries
Protein Function (UniProtKB)
Ensures the proper localization of the mRNA of the bicoid gene to the anterior regions of the oocyte thus playing a fundamental role in the establishment of the polarity of the oocyte. May bind the bcd mRNA.
(UniProt, P28750)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
exu: exuperantia (T. Schupbach)
Maternal-effect lethal mutant; embryos from homozygous mothers lack anterior-most head structures. Instead they form an inverted posterior midgut and proctodeal region at their anterior end. Cephalic furrow at gastrulation is shifted towards anterior. Analysis of germline clones indicates that the mutation is germline autonomous (Schupbach and Wieschaus, l986, Dev. Biol. 113: 443-48). Causes shift in blastoderm fate map as indicated by ftz expression; thoracic stripes broadened and shifted anteriorly; abdominal stripes narrowed and compressed posteriorly (Mlodzik et al.). Eggs produced by exu mothers appear to have a more uniform distribution of bcd+ product, i.e., less concentration anteriorly (Fronhofer and Nusslein-Volhard).
Summary (Interactive Fly)

a noncanonical RNA-binding protein with EXO-SAM-like domain architecture that interacts with its target RNA as a homodimer a core component of a large protein complex involved in localizing mRNAs both within nurse cells and the developing oocyte

Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\exu 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 P28750)

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
PDB - An information portal to biological macromolecular structures
Comments on Gene Model

Gene model reviewed during 5.51

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0086242
2320
532
FBtr0086243
1988
532
FBtr0086244
2621
532
FBtr0302285
2631
532
Additional Transcript Data and Comments
Reported size (kB)

3.0, 2.3 (northern blot)

2.9, 2.5, 2.1 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0085555
58.0
532
10.11
FBpp0085556
58.0
532
10.11
FBpp0085557
58.0
532
10.11
FBpp0291491
58.0
532
10.11
Polypeptides with Identical Sequences

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

532 aa isoforms: exu-PA, exu-PB, exu-PC, exu-PD
Additional Polypeptide Data and Comments
Reported size (kDa)

532 (aa); 58 (kD)

Comments
External Data
Subunit Structure (UniProtKB)

Component of the osk RNP complex, which is composed of at least exuperantia (exu), ypsilon schachtel (yps), aret (bruno), cup, and the mRNA of osk (PubMed:10662770). In the sponge body, forms a ribonucleoprotein complex (RNP) containing at least me31B, exu, yps and the mRNA of osk; interactions with exu and yps are RNA dependent (PubMed:11546740).

(UniProt, P28750)
Crossreferences
InterPro - A database of protein families, domains and functional sites
PDB - An information portal to biological macromolecular structures
Linkouts
Sequences Consistent with the Gene Model
Nucleotide / Polypeptide Records
 
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\exu 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).

4.09

Transcript Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
pole plasm

Comment: maternally deposited

organism

Comment: maternally deposited

northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

The male exu transcript is present in late larval, pupal, and adult stages.

The exu 2.9kb transcript is specific to males and is limited to the germline, since flies without germ cells, produced from tud mothers, lack sex-specific transcripts.

Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
located_in cytoplasm
located_in P-body
inferred from direct assay
inferred from high throughput direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\exu in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
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) 9-10
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 19 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 32 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of exu
Transgenic constructs containing regulatory region of exu
Aberrations (Deficiencies and Duplications) ( 10 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Sterility
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (2)
1 of 14
Yes
No
1  
1 of 14
Yes
No
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (2)
1 of 14
Yes
No
1 of 14
Yes
No
Mus musculus (laboratory mouse) (2)
1 of 14
Yes
No
1 of 14
Yes
No
Xenopus tropicalis (Western clawed frog) (0)
Danio rerio (Zebrafish) (2)
1 of 14
Yes
No
1 of 14
Yes
No
Caenorhabditis elegans (Nematode, roundworm) (0)
Anopheles gambiae (African malaria mosquito) (3)
12 of 12
Yes
Yes
10 of 12
No
Yes
Arabidopsis thaliana (thale-cress) (0)
Saccharomyces cerevisiae (Brewer's yeast) (0)
Schizosaccharomyces pombe (Fission yeast) (0)
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:exu. Refer to their site for version information.
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 ( 0 )
    Allele
    Disease
    Interaction
    References
    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?
    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
    esyN Network Diagram
    Show neighbor-neighbor interactions:
    Show/hide secondary interactors 
    (data from AllianceMine provided by esyN)
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Interactions Browser

    Please see the Physical Interaction reports below for full details
    MIST Molecular Interaction Search Tool

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    RNA-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    esyN Network Diagram
    Show/hide secondary interactors 
    (data from AllianceMine provided by esyN)
    esyN Network Key:
    Suppression
    Enhancement

    Please look at the allele data for full details of the genetic interactions
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Subunit Structure (UniProtKB)
    Component of the osk RNP complex, which is composed of at least exuperantia (exu), ypsilon schachtel (yps), aret (bruno), cup, and the mRNA of osk (PubMed:10662770). In the sponge body, forms a ribonucleoprotein complex (RNP) containing at least me31B, exu, yps and the mRNA of osk; interactions with exu and yps are RNA dependent (PubMed:11546740).
    (UniProt, P28750 )
    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
    External Data
    Linkouts
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    2R
    Recombination map
    2-91
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    57A9-57A10
    Limits computationally determined from genome sequence between P{lacW}l(2)k02206k02206 and P{lacW}l(2)k06409k06409&P{PZ}insc05475
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    57A4-57B1
    (determined by in situ hybridisation)
    Tentative cytological location determined by segmental aneuploidy.
    Experimentally Determined Recombination Data
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (23)
    Genomic Clones (26)
    cDNA Clones (154)
     

    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)
    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

        exu protein is highly enriched in the sponge bodies, subcellular structures in nurse cells. Neither the accumulation of, or level of exu protein is dependent on the amount of bcd mRNA present in the ovaries. Results propose that sponge bodies are structures that, by assembly and transport of included molecules or associated structures, are involved in localisation of mRNAs in oocytes.

        Deletions within the male-specific 3'-UTR lead to male sterility associated with reduced steady-state levels of the mutant mRNA in vivo.

        An ovarian protein, exl binds to BLE1, an RNA localisation element from bcd mRNA. exl localisation is disrupted in exu mutants suggesting exl and exu proteins interact.

        tra2 is required in male germ cells for efficient male-specific processing of exu RNA. In the absence of tra2 males produce a new exu mRNA which is processed at its 3' end so that it contains sequences normally specific to the female 3' untranslated region. The male and female mRNAs differ in the untranslated regions so the predicted polypeptide is the same.

        Drug studies indicate that the Avic\GFP exu fusion protein is co-localised with microtubules during oogenesis. These particles are RNP complexes which transport and target bcd mRNA to the oocyte anterior cortex.

        In vitro binding and precipitation assays show that bacterially expressed exu protein binds to tubulin. Particles seen with the exu Avic\GFP fusion protein are RNP complexes that bind bcd mRNA, the particles associate with microtubules via exu in nurse cells and is transported along the microtubules and targetted to the anterior cortex of the oocyte.

        Comparison of bcd and hts transcript distribution in swa, exu and stau mutant embryos indicates different genetic requirements for proper localization of bcd and hts RNAs.

        exu is required for the proper localization of bcd mRNA in the oocyte.

        bcd mRNA localization requires the function of at least three genes, the exu gene acts earliest in the pathway. exu acts in initiating bcd mRNA localization but does not play a persistant role in that process.

        exu is not required for the maintenance of bcd mRNA localization during late stages of oogenesis or early embryogenesis. It is required for the establishment of bcd mRNA localization in the developing oocyte.

        Mutations in maternal anterior class gene exu interact with RpII140wimp.

        The effects of taxol treatment on exu mutants suggest general roles for the exu gene product in the multi-step bcd mRNA localization process.

        In embryos from exu mutant females bcd transcripts are delocalized and exposed to nos activity in the posterior.

        exu mutants exhibit weak anterior deletions, and weak segmentation defects in the posterior abdomen.

        Mature follicles are immunologically stained for asymmetric distribution of ecdysteroid-related antigen. During late oogenesis localisation of the antigen changes dramatically suggesting the antigen plays a role in early embryogenesis and, perhaps, in pattern formation.

        Mutations in exu result in a maternal effect phenotype with defects during the early stages of gastrulation and defects in the anteroposterior axis.

        exu mutations disrupt the second stage of bcd RNA localization during oogenesis, localization to the apical regions of the nurse cells.

        Mutations at exu cause anterior defects, rarely posterior defects in the embryo.

        Relationship to Other Genes
        Source for database merge of
        Additional comments
        Nomenclature History
        Source for database identify of

        Source for identity of: exu CG8994

        Nomenclature comments
        Etymology
        Synonyms and Secondary IDs (8)
        Reported As
        Secondary FlyBase IDs
          Datasets (0)
          Study focus (0)
          Experimental Role
          Project
          Project Type
          Title
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 75 )
          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 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)
          PDB - An information portal to biological macromolecular structures
          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)
          Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
          MIST (protein-protein) - An integrated Molecular Interaction Database
          References (260)