FB2026_02 , released June 18, 2026
Gene: Dmel\stnA
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General Information
Symbol
Dmel\stnA
Species
D. melanogaster
Name
stoned A
Annotation Symbol
CG12500
Feature Type
FlyBase ID
FBgn0016976
Gene Model Status
Stock Availability
Gene Summary
Adapter protein involved in endocytic recycling of synaptic vesicles membranes. May act by mediating the retrieval of synaptotagmin protein Syt from the plasma membrane, thereby facilitating the internalization of multiple synaptic vesicles from the plasma membrane. (UniProt, Q24211)
Contribute a Gene Snapshot for this gene.
Also Known As

stn, stoned, l(1)X-3, X-3, stn-A

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
1-66
RefSeq locus
NC_004354 REGION:22980722..23004648
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (5 terms)
Molecular Function (1 term)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
inferred from physical interaction with UniProtKB:P21521
inferred from physical interaction with UniProtKB:Q24212
Terms Based on Predictions or Assertions (0 terms)
Biological Process (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from mutant phenotype
Terms Based on Predictions or Assertions (0 terms)
Cellular Component (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from direct assay
located_in synaptic vesicle
inferred from genetic interaction with FLYBASE:Syt1; FB:FBgn0004242
inferred from physical interaction with FLYBASE:Csp; FB:FBgn0004179
inferred from physical interaction with FLYBASE:Syt1; FB:FBgn0004242
Terms Based on Predictions or Assertions (0 terms)
Gene Group (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
    -
    Summaries
    Gene Group (FlyBase)
    STONINS -
    The stoned proteins, stoned A and B, are encoded by a dicistronic locus in insecta. They are structurally different, but both contain motifs that are found in adaptor proteins. The stoned proteins are believed to act in synaptic vesicle recycling pathways. (Adapted from FBrf0139751 and FBrf0209527).
    Protein Function (UniProtKB)
    Adapter protein involved in endocytic recycling of synaptic vesicles membranes. May act by mediating the retrieval of synaptotagmin protein Syt from the plasma membrane, thereby facilitating the internalization of multiple synaptic vesicles from the plasma membrane.
    (UniProt, Q24211)
    Phenotypic Description (Red Book; Lindsley and Zimm 1992)
    stn: stoned (J.C. Hall)
    Exists as temperature-sensitive behavioral, temperature-sensitive lethal, and unconditionally lethal alleles. Severe behavioral debilitation is quickly induced by shift of adult stn6 and stn7 from 25 to 29; abnormalities at high temperature include uncoordinated leg and wing movements, with complete paralysis never occurring (e.g., legs still move); stn6 causes some debilitation at 22 (slow movements, occasionally falling over); whereas stn7 is more nearly normal at low temperatures, and can even walk with difficulty at 29; at permissive temperatures, stn (allele unspecified) causes unusual jump response to light-off stimulus, which is more pronounced in combination with w (Kelly, 1983b); associated with this abnormal jumping is an increase in amplitude of light-off transient spike of electroretinogram (ERG); in tests of light-adapted mutant, the jump response, as monitored by recordings from indirect flight muscles, habituates with increasing frequencies of light-off stimulation (Kelly, 1983b); combining stn with tan, which by itself leads to decreased amplitude of ERG on and off transients, leads to loss of anomalous jumping and partial restoration of light-off spike. In biochemical experiments, stn (allele unspecified) found to cause accentuation of in vivo phosphorylation of a protein from adult head synaptosomal fractions that is modified in this way by a cAMP-dependent protein kinase, with such phosphorylation being enhanced by exposure of flies to light, prior to extraction (Kelly, 1983a). A protein, which has same molecular weight as the one noted above, found to be phosphorylated in vitro by a fly-derived Ca2+-calmodulin-dependent protein kinase; stn causes increased levels of in vivo phosphorylation of this material (Kelly, 1983b). The temperature-sensitive lethal allele, stn, leads to brief paralysis, followed by sporadic movements, as a result of mechanical shocking (Homyk and Sheppard, 1977, Genetics 87: 95-104); other abnormalities include abnormally short jump and flight distances, apparent absence of on and off transients in ERG, and lethality when raised at 29. Effects of three of the lethal alleles, stn1, stn11, and stn14, were examined during development for effects on gross anatomy of CNS or PNS; no obvious abnormalities were observed (Perrimon et al., 1989).
    Summary (Interactive Fly)

    a dicistronic locus encoding two proteins involved in synaptic vesicle recycling

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

    Please see the JBrowse view of Dmel\stnA 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 Q24211)

    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 5.53

    Gene model reviewed during 5.52

    Gene model reviewed during 5.54

    Transcript Data
    Annotated Transcripts
    Name
    FlyBase ID
    RefSeq ID
    Length (nt)
    Assoc. CDS (aa)
    FBtr0301618
    8144
    850
    FBtr0301619
    8270
    850
    FBtr0344112
    8332
    850
    FBtr0344465
    8207
    850
    Additional Transcript Data and Comments
    Reported size (kB)

    8.4 (northern blot)

    Comments
    External Data
    Crossreferences
    Polypeptide Data
    Annotated Polypeptides
    Name
    FlyBase ID
    Predicted MW (kDa)
    Length (aa)
    Theoretical pI
    UniProt
    RefSeq ID
    GenBank
    FBpp0290833
    93.1
    850
    4.19
    FBpp0290834
    93.1
    850
    4.19
    FBpp0310531
    93.1
    850
    4.19
    FBpp0310836
    93.1
    850
    4.19
    Polypeptides with Identical Sequences

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

    850 aa isoforms: stnA-PC, stnA-PD, stnA-PE, stnA-PF
    Additional Polypeptide Data and Comments
    Reported size (kDa)

    850 (aa); 145 (kD observed)

    Comments

    Although the predicted molecular weight of the

    stnA protein is 93 kD, its apparent molecular weight is 145 kD. The

    stnA fusion protein also exhibited lower than expected mobility on

    SDS-PAGE.

    Under reducing SDS-PAGE conditions, the stnA protein migrates at 70kD.

    The stnA protein is highly acidic, and contains no cysteine or internal

    methionine residues.

    External Data
    Subunit Structure (UniProtKB)

    Interacts with the second C2 domain of Syt.

    (UniProt, Q24211)
    Domain

    The Asp-Pro-Phe (DPF) motifs, which are found in many presynatic proteins, are thought to mediate an interaction with AP-2alpha.

    (UniProt, Q24211)
    Crossreferences
    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\stnA 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).

    -0.74

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

    The stnA protein is detected at high levels in the adult head, and at much lower levels in the thorax and abdomen.

    Marker for
     
    Subcellular Localization
    CV Term
    Evidence
    References
    inferred from direct assay
    located_in synaptic vesicle
    inferred from genetic interaction with FLYBASE:Syt1; FB:FBgn0004242
    inferred from physical interaction with FLYBASE:Csp; FB:FBgn0004179
    inferred from physical interaction with FLYBASE:Syt1; FB:FBgn0004242
    Expression Deduced from Reporters
    High-Throughput Expression Data
    Associated Tools

    JBrowse - Visual display of RNA-Seq signals

    View Dmel\stnA 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
    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
    Images
    Alleles, Insertions, Transgenic Constructs, and Aberrations
    Classical and Insertion Alleles ( 23 )
    For All Classical and Insertion Alleles Show
     
    Other relevant insertions
    Transgenic Constructs ( 4 )
    For All Alleles Carried on Transgenic Constructs Show
    Transgenic constructs containing/affecting coding region of stnA
    Transgenic constructs containing regulatory region of stnA
    Aberrations (Deficiencies and Duplications) ( 238 )
    Inferred from experimentation ( 238 )
    Gene disrupted in
    Gene not disrupted in
    Inferred from location ( 4 )
    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
    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) (0)
    Model Organism Orthologs (via DIOPT v9.1)
    Species\Gene Symbol
    Score
    Best Score
    Best Reverse Score
    Alignment
    Complementation?
    Transgene?
    Rattus norvegicus (Norway rat) (0)
    Mus musculus (laboratory mouse) (0)
    Xenopus tropicalis (Western clawed frog) (0)
    Danio rerio (Zebrafish) (0)
    Caenorhabditis elegans (Nematode, roundworm) (0)
    Anopheles gambiae (African malaria mosquito) (1)
    10 of 12
    Yes
    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:stnA. 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
      Interaction Browsers

      Please see the Physical Interaction reports below for full details
      protein-protein
      Physical Interaction
      Assay
      References
      Summary of Genetic Interactions
      Interaction Browsers

      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 with the second C2 domain of Syt.
      (UniProt, Q24211 )
      Linkouts
      BioGRID - A database of protein and genetic interactions.
      DroID - A comprehensive database of gene and protein interactions.
      MIST (genetic) - An integrated Molecular Interaction Database
      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)
      X
      Recombination map
      1-66
      Cytogenetic map
      Sequence location
      FlyBase Computed Cytological Location
      Cytogenetic map
      Evidence for location
      20F3-20F3
      Experimentally Determined Cytological Location
      Cytogenetic map
      Notes
      References
      Experimentally Determined Recombination Data
      Left of (cM)
      Notes
      Stocks and Reagents
      Stocks (13)
      Genomic Clones (6)
       

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

      cDNA Clones (103)
       

      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

            Rescue analysis suggests that the stnB open reading frame (ORF) encodes all vital and important functions of the dicistronic "stn" locus and that the stnA ORF encodes a dispensible protein. However, this interpretation is limited by the absence of a true null for "stn" due to partial rescue of presynaptic stnA protein by transgenically provided stnB protein.

            Neuronal expression of a dicistronic "stn" transcript (encoding both stnA and stnB proteins) is sufficient to rescue various phenotypic defects of "stn" mutants, including lethality and defects in evoked transmitter release and syt protein localisation at the nerve terminals. In addition, neural expression of a monocistronic stnB transgene is sufficient to rescue all these defects. In contrast, neural expression of a monocistronic stnA transgene does not rescue any of the "stn" mutant phenotypes. In addition, "stn" is required for regulating normal growth and morphology of the motor terminal, and this function is also provided by a monocistronic stnB transgene.

            "stn" mutants show a striking decrease in the size of the endo-exo-cycling synaptic vesicle pool and loss of spatial regulation of the vesicular recycling intermediates. Mutant synapses display a significant delay in vesicular membrane retrieval after depolarisation and neurotransmitter release.

            Expression analysis suggests that mutation in the first open reading frame, stnA, of the stoned dicistronic transcript renders the second reading frame, stnB, unreadable.

            The stnA and stnB proteins are essential for the recycling of synaptic vesicle membrane and are required for the proper sorting of the syt gene product during endocytosis.

            The 'stoned' locus produces a dicistronic transcript and encodes two distinct polypeptides.

            The stnA gene product interacts directly or indirectly with the cAMP second messenger system, synaptic membrane recycling pathway and with biogenic amine metabolism.

            stnA functions either in the nervous system or in both the nervous system and the musculature, but is not required for gross neural development. Mutations at stnA show allele-specific interactions with mutations at dnc and shi.

            Exists as temperature-sensitive behavioral, temperature-sensitive lethal, and unconditionally lethal alleles. Combining stnA with t, which by itself leads to decreased amplitude of ERG on and off transients, leads to loss of anomalous jumping and partial restoration of light-off spike.

            Mutations of stnA cause abnormalities in the electroretinogram (ERG) and/or prolonged depolarization after potential (PDA).

            Relationship to Other Genes
            Source for database merge of
            Additional comments

            One or more of the processed transcripts for this gene contain(s) two non-overlapping open reading frames (ORFs). The non-overlapping ORFs are represented by stnA and stnB.

            Nomenclature History
            Source for database identify of
            Nomenclature comments
            Etymology
            Synonyms and Secondary IDs (29)
            Reported As
            Secondary FlyBase IDs
            • FBan0012500
            • FBgn0003533
            • FBgn0058306
            • FBgn0063778
            Datasets (0)
            Study focus (0)
            Experimental Role
            Project
            Project Type
            Title
            Study result (0)
            Result
            Result Type
            Title
            External Crossreferences and Linkouts ( 39 )
            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.
            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
            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.
            FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
            iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
            Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
            MIST (genetic) - An integrated Molecular Interaction Database
            MIST (protein-protein) - An integrated Molecular Interaction Database
            References (96)