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General Information
Symbol
Dmel\comm
Species
D. melanogaster
Name
commissureless
Annotation Symbol
CG17943
Feature Type
FlyBase ID
FBgn0010105
Gene Model Status
Stock Availability
Gene Snapshot
commissureless (comm) product regulates the cell surface localization of Robo axon guidance receptors by intercepting them in the ER/Golgi during exocytosis or removing them from the surface by endocytosis. comm is required for formation of the CNS axon scaffold and synaptogenesis. [Date last reviewed: 2018-09-13]
Key Links
Genomic Location
Cytogenetic map
Sequence location
3L:15,721,511..15,728,430 [-]
Recombination map

3-43

RefSeq locus
NT_037436 REGION:15721511..15728430
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the commissureless family. (Q24139)
Protein Signatures (InterPro)
Molecular Function (GO)
[Detailed GO annotations]
Experimental Evidence
Predictions / Assertions
-
Summaries
Gene Group (FlyBase)
COMMISSURELESS -
Comm family proteins are single-pass transmembrane proteins with roles in arthropod embryonic nerve cord development. The prototypic family member, commissureless (comm), acts as an endosome sorting receptor for robo1, directing it to the late endosomal-lysosomal pathway and therefore down-regulating its expression. (Adapted from FBrf0151706, FBrf0151911).
Protein Function (UniProtKB)
Controls axon guidance across the CNS midline by preventing the delivery of Robo to the growth cone.
(UniProt, Q24139)
Summary (Interactive Fly)
Gene Model and Products
Number of Transcripts
2
Number of Unique Polypeptides
1

Please see the GBrowse view of Dmel\comm or the JBrowse view of Dmel\comm 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
Comments on Gene Model

Tissue-specific extension of 3' UTRs observed during later stages (FBrf0218523, FBrf0219848); all variants may not be annotated

Gene model reviewed during 5.45

Gene model reviewed during 5.46

Gene model reviewed during 5.56

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0075579
1678
370
FBtr0333023
2495
370
Additional Transcript Data and Comments
Reported size (kB)

1.7, 1.0 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0075332
40.3
370
5.04
FBpp0305237
40.3
370
5.04
Polypeptides with Identical Sequences

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

370 aa isoforms: comm-PA, comm-PB
Additional Polypeptide Data and Comments
Reported size (kDa)

370 (aa); 40 (kD predicted)

Comments
External Data
Subunit Structure (UniProtKB)

Interacts (probably via PY-motifs) with Nedd4 (via WW2 domain) (PubMed:12165468, PubMed:16531238). Interacts with Robo (PubMed:12165468).

(UniProt, Q24139)
Post Translational Modification

Ubiquitinated by Nedd4; which promotes endocytosis of the comm/robo complex and comm proteasomal degradation (PubMed:12165468). Not ubiquitinated by Nedd4 (PubMed:15657595).

(UniProt, Q24139)
Domain

The cytoplasmic domain is required for function in axon guidance.

(UniProt, Q24139)
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\comm using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Gene Ontology (22 terms)
Molecular Function (3 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
inferred from physical interaction with UniProtKB:Q9VVI3
(assigned by UniProt )
inferred from physical interaction with FLYBASE:Nedd4; FB:FBgn0259174
inferred from physical interaction with UniProtKB:Q9W213
inferred from physical interaction with FLYBASE:Nedd4; FB:FBgn0259174
inferred from direct assay
Terms Based on Predictions or Assertions (0 terms)
Biological Process (12 terms)
Terms Based on Experimental Evidence (10 terms)
CV Term
Evidence
References
inferred from genetic interaction with FLYBASE:fra; FB:FBgn0011592
inferred from mutant phenotype
(assigned by UniProt )
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from direct assay
(assigned by UniProt )
inferred from mutant phenotype
Terms Based on Predictions or Assertions (6 terms)
CV Term
Evidence
References
Cellular Component (7 terms)
Terms Based on Experimental Evidence (7 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by UniProt )
inferred from direct assay
Terms Based on Predictions or Assertions (0 terms)
Expression Data
Expression Summary Ribbons
Colored tiles in ribbon indicate that expression data has been curated by FlyBase for that anatomical location. Colorless tiles indicate that there is no curated data for that location.
For complete stage-specific expression data, view the modENCODE Development RNA-Seq section under High-Throughput Expression below.
Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
antennal primordium

Comment: reported as procephalic ectoderm primordium

central brain primordium

Comment: reported as procephalic ectoderm primordium

visual primordium

Comment: reported as procephalic ectoderm primordium

dorsal head epidermis primordium

Comment: reported as procephalic ectoderm primordium

lateral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

ventral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

Additional Descriptive Data

In stage 14 embryos, comm is expressed in commissural neurons including the EG neurons.

comm expression is strong and dynamic in the embryonic nervous system. At embryonic stage 13, it is detected in neurons close to the midline and in midline glial cells. At stage 14, expression is detected throughout the ventral nerve cord and it is expressed to high levels in lateral neurons. At stage 15, expression has declined drastically in the nerve cord.

comm expression is first observed during the cellular blastoderm stage in a pattern of six pair-rule stripes. Stripe 3 is initially missing but subsequently appears. By stage 6, the stripes narrow and interstripes appear forming a pattern of 14 stripes which persist until stage 10. At this time expression is seen in two longitudinal stripes located just lateral to the neurogenic region and extending the length of the segmented embryo. A segmentally repeated pattern is also observed in the emerging CNS. comm is expressed in a subset of neuroblasts and in some ganglion mother cells. By stage 12, expression is observed in the midline of the CNS and in the visceral mesoderm. Along the midline, expression becomes restricted to a subset of cells located at the anterior part of each neuromere. There is also transient expression in neurons just lateral to the midline cells including RP1 and RP3. Double labeling experiments show that these cells lie along the path that the first commissural axons take to reach the midline. From their position, they are thought to be the anterior two pairs of midline glia. comm expression ceases in stage 16.

The 1.0kb comm transcripts are less abundant than the 1.7kb transcripts and differ only in the site of polyadenylation.

Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

comm protein appears to accumulate predominantly within intracellular vesicles with a low level present on the plasma membrane. The comm protein likely cycles from the Golgi to the cell surface where some of it is endocytosed.

comm protein is expressed in the same cells that express comm RNA. In addition, it is observed in the first commissural axons that contact comm-expressing midline glia. It is expressed along their axons and not in the neuronal cell bodies. It therefore appears that comm protein is exported from midline cells to decorate commissural axons. In addition to the commissural axons, comm protein staining is observed in vesicles within many neuronal cell bodies throughout the nerve cord. It is thought that this represents internalization of comm protein from the surface of axons following transfer of comm protein from midline glia.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by UniProt )
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\comm in GBrowse 2
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
FLIGHT - Cell culture data for RNAi and other high-throughput technologies
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
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) 4-6
  • Stages(s) 7-8
  • Stages(s) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 25 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 58 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of comm
Transgenic constructs containing regulatory region of comm
Deletions and Duplications ( 5 )
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
chordotonal organ & embryo & nerve terminal, with Scer\GAL412.1
ventral nerve cord commissure & larval brain | somatic clone
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (0)
No records found.
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (0)
No records found.
Rattus norvegicus (Norway rat) (0)
No records found.
Xenopus tropicalis (Western clawed frog) (0)
No records found.
Danio rerio (Zebrafish) (0)
No records found.
Caenorhabditis elegans (Nematode, roundworm) (0)
No records found.
Arabidopsis thaliana (thale-cress) (0)
No records found.
Saccharomyces cerevisiae (Brewer's yeast) (0)
No records found.
Schizosaccharomyces pombe (Fission yeast) (0)
No records found.
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG09190DE9 )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila melanogaster
fruit fly
Drosophila simulans
Drosophila sechellia
Drosophila erecta
Drosophila yakuba
Drosophila yakuba
Drosophila ananassae
Drosophila pseudoobscura pseudoobscura
Drosophila persimilis
Drosophila willistoni
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG091505L4 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( None identified )
No non-Dipteran orthologies identified
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( None identified )
No non-Insect Arthropod orthologies identified
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( None identified )
No non-Arthropod Metazoa orthologies identified
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (2)
1 of 10
1 of 10
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Model Summary Ribbon
    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 v7.1 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:
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Interactions Browser

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    esyN Network Diagram
    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)
    Interacts (probably via PY-motifs) with Nedd4 (via WW2 domain) (PubMed:12165468, PubMed:16531238). Interacts with Robo (PubMed:12165468).
    (UniProt, Q24139 )
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
    MIST (genetic) - An integrated Molecular Interaction Database
    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)
    3L
    Recombination map

    3-43

    Cytogenetic map
    Sequence location
    3L:15,721,511..15,728,430 [-]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    71F2-71F2
    Limits computationally determined from genome sequence between P{EP}Tfb2EP572 and P{lacW}thj5C8&P{PZ}Mbs03802
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    71E3-71E5
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (12)
    Genomic Clones (31)
    cDNA Clones (36)
     

    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 GBrowse for alignment of the cDNAs and ESTs to the gene model.

    cDNA clones, fully sequences
    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
    GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
    Antibody Information
    Laboratory Generated Antibodies
     

    polyclonal

    Commercially Available Antibodies
     
    Other Information
    Relationship to Other Genes
    Source for database identify of
    Source for database merge of
    Additional comments
    Other Comments

    The absence of elav affects neuronal expression of comm.

    dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.

    comm acts as a sorting receptor for robo, diverting it from synthetic to the late endocytic pathway. comm seems to be required in the commissural neurons not in midline cells for midline crossing.

    The intracellular region of comm is essential for the downregulation of robo. comm redistributes robo away from the cell surface. robo and comm form a stable complex in S2 cells. comm is a specific binding partner and substrate of Nedd4.

    Two EMS induced alleles were identified in a screen for mutations affecting commissure formation in the CNS of the embryo.

    comm downregulates robo expression.

    comm controls growth cone guidance across the CNS midline and encodes a novel membrane protein. As commissural growth cones contact and traverse the CNS midline, the comm protein is apparently transferred from midline glia to commissural axons.

    The comm gene product is required for commissural growth cones to bypass a general repulsive system operating at the midline. In the absence of comm commissural growth cones that are attracted to the midline by other mechanisms are unable to cross and ultimately retract their commissural projections.

    The comm gene product plays a role in the attractive signalling system, a component of the mechanism that guides growth cones towards and away from the midline. In mutant embryos the growth cones of commissural neurons do not project across the midline, but extend only on their own side of the central nervous system (CNS).

    Mutant alleles show absent commissural axon pathways in the embryonic ventral nerve cord.

    Origin and Etymology
    Discoverer
    Etymology
    Identification
    External Crossreferences and Linkouts ( 33 )
    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/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
    BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
    Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
    Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
    Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
    Flygut - An atlas of the Drosophila adult midgut
    GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
    InterPro - A database of protein families, domains and functional sites
    KEGG Genes - Molecular building blocks of life in the genomic space.
    modMine - A data warehouse for the modENCODE project
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    DRSC - Results frm RNAi screens
    FLIGHT - Cell culture data for RNAi and other high-throughput technologies
    FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
    FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
    FlyMine - An integrated database for Drosophila genomics
    Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
    InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
    MIST (genetic) - An integrated Molecular Interaction Database
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Synonyms and Secondary IDs (6)
    Reported As
    Secondary FlyBase IDs
      Datasets (0)
      Study focus (0)
      Experimental Role
      Project
      Project Type
      Title
      References (212)