FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\hook
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General Information
Symbol
Dmel\hook
Species
D. melanogaster
Name
hook
Annotation Symbol
CG10653
Feature Type
FlyBase ID
FBgn0001202
Gene Model Status
Stock Availability
Gene Summary
hook (hook) encodes a microtubule-binding protein involved in cytoskeleton-dependent intracellular transport. Its knockdown results in hooked bristles, but it is not required for viability. [Date last reviewed: 2022-05-19] (FlyBase Gene Snapshot)
Also Known As

hk

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
2-54
RefSeq locus
NT_033779 REGION:19030844..19033498
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (11 terms)
Molecular Function (3 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from physical interaction with FLYBASE:Rab5; FB:FBgn0014010
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000436622
inferred from electronic annotation with InterPro:IPR008636
Biological Process (4 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
inferred from mutant phenotype
involved_in endocytosis
inferred from expression pattern
inferred from expression pattern
inferred from mutant phenotype
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000436622
inferred from electronic annotation with InterPro:IPR008636
inferred from biological aspect of ancestor with PANTHER:PTN000436622
inferred from electronic annotation with InterPro:IPR043936
involved_in endocytosis
traceable author statement
Cellular Component (4 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
located_in endosome
inferred from direct assay
located_in synapse
inferred from mutant phenotype
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
is_active_in centrosome
inferred from biological aspect of ancestor with PANTHER:PTN001055559
is_active_in cytoplasm
inferred from biological aspect of ancestor with PANTHER:PTN000436622
located_in cytoplasm
non-traceable author statement
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the hook family. (Q24185)
Summaries
Gene Snapshot
hook (hook) encodes a microtubule-binding protein involved in cytoskeleton-dependent intracellular transport. Its knockdown results in hooked bristles, but it is not required for viability. [Date last reviewed: 2022-05-19]
Protein Function (UniProtKB)
Involved in endocytic trafficking by stabilizing organelles of the endocytic pathway. Probably acts as a cytoskeletal linker protein required to tether endosome vesicles to the cytoskeleton. Involved in modulation of endocytosis at stages required for down-regulation of membrane proteins that control synapse size. Not involved in synaptic vesicle recycling. Required in R7 cells for boss endocytosis into multivesicular bodies (MVBs). Has a role in regulating adult longevity.
(UniProt, Q24185)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
hk: hook
thumb
hk: hook
From Mohr, 1927, Hereditas 9: 169-79.
Bristles nearly all hooked at tip or blunted, some bent at right angles. Scutellars and verticals especially affected. Acrostichal hairs fewer and outer rows separated. Eyes slightly roughened. Wings usually divergent and may be smaller. Body sometimes small and chunky. Less extreme expression at 19, especially the wing character, but classification reliable. RK2.
Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\hook 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 Q24185)

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

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

Gene model reviewed during 5.48

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0081180
2317
679
Additional Transcript Data and Comments
Reported size (kB)

2.3 (longest cDNA)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0080722
76.7
679
4.99
Polypeptides with Identical Sequences

There is only one protein coding transcript and one polypeptide associated with this gene

Additional Polypeptide Data and Comments
Reported size (kDa)

679 (aa); 85 (kD observed); 77 (kD predicted)

Comments
External Data
Subunit Structure (UniProtKB)

Homodimer. Interacts with microtubules via its N-terminus.

(UniProt, Q24185)
Domain

The coiled coil domain mediates homodimerization.

(UniProt, Q24185)
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\hook using the Feature Mapper tool.

External Data
Crossreferences
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).

-0.35

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
organism

Comment: maternally deposited

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

Comment: reference states 44 hours APF

mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
western blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

The multivesicular bodies in which hk protein is detected are a component of the general endocytic compartment. In embryos, cortical areas of cells stain for hk protein in a punctate pattern. In the oocyte, a similar cortical localization is detected, while in the nurse cell, staining is even throughout the cytoplasm.

hk protein localization is restricted to the perimeter of large endosomes in Schneider2:Sev cells, while dor protein is found internally as well.

The hk protein is detected in all developmental stages, from the embryo to the adult.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in endosome
inferred from direct assay
located_in synapse
inferred from mutant phenotype
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\hook 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
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 20 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 14 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of hook
Transgenic constructs containing regulatory region of hook
Aberrations (Deficiencies and Duplications) ( 56 )
Inferred from experimentation ( 56 )
Gene not disrupted in
Inferred from location ( 10 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (10)
12 of 14
Yes
Yes
11 of 14
No
Yes
10 of 14
No
Yes
2  
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
1 of 14
No
No
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (7)
11 of 14
Yes
Yes
10 of 14
No
Yes
5 of 14
No
Yes
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (10)
12 of 14
Yes
Yes
11 of 14
No
Yes
9 of 14
No
Yes
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (6)
9 of 13
Yes
Yes
9 of 13
Yes
Yes
8 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Danio rerio (Zebrafish) (7)
11 of 14
Yes
Yes
6 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
Yes
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (3)
6 of 14
Yes
Yes
1 of 14
No
No
1 of 14
No
Yes
Anopheles gambiae (African malaria mosquito) (4)
12 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:hook. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (3)
3 of 13
1 of 13
1 of 13
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 ( 3 )
    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
    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)
    Homodimer. Interacts with microtubules via its N-terminus.
    (UniProt, Q24185 )
    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
    KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    2L
    Recombination map
    2-54
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    37B10-37B10
    Limits computationally determined from genome sequence between P{lacW}l(2)37Dbk16106&P{lacW}Catsupk05424 and P{lacW}Ddck02104
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    37B10-37B10
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location

    2-53.9

    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (76)
    Genomic Clones (27)
    cDNA Clones (41)
     

    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

          S2 cells treated with dsRNA generated against this gene show reduced phagocytosis of Candida albicans compared to untreated cells.

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

          hk is required for the normal endocytic trafficking of different classes of ligands.

          hk is required late in endocytic trafficking to negatively regulate delivery from mature multivesicular bodies to multilammelar late endosomes and lysosomes.

          Mutants do not exhibit defects in the denticle belt of hairs of the larvae.

          Mutations in hk inhibit the accumulation of boss protein in multivesicular bodies in R7 cells. hk is molecularly characterised and results indicate the hk protein is a novel component of the endocytic compartment.

          hk protein constitutes a new component of the endocytotic compartment, lack of boss internalisation into the R7 precursor cell is a direct consequence of hk mutations.

          Located between coordinates -85.2 and -82.5.

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

          Source for identity of: hook hk

          Nomenclature comments

          Renamed from 'hk' to 'hook' to reduce confusion with the 'Hk' ('Hyperkinetic') gene symbol, from which it differed only by case.

          Etymology
          Synonyms and Secondary IDs (5)
          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
          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
          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)
          KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
          MIST (genetic) - An integrated Molecular Interaction Database
          MIST (protein-protein) - An integrated Molecular Interaction Database
          References (131)