FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\pck
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General Information
Symbol
Dmel\pck
Species
D. melanogaster
Name
pickel
Annotation Symbol
CG14779
Feature Type
protein_coding_gene
FlyBase ID
FBgn0013720
Gene Model Status
Current
Stock Availability
10 publicly available
Gene Summary
pickel (pck) encodes a transmembrane protein of the Claudin superfamily. It is part of the septate junction (SJ) core complex and essential for SJ morphogenesis and function. The transepithelial barrier function of epithelial tissues is affected in pck mutants. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
All Summaries
Also Known As

mega, Megatrachea, EG:80H7.2 , l(1)G0044

Key Links
Genomic Location
Cytogenetic map
2A4-2A4
Sequence location
Recombination map
1-0.2
RefSeq locus
NC_004354 REGION:1470666..1472325
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 (7 terms)
Molecular Function (0 terms)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (0 terms)
Biological Process (5 terms)
Terms Based on Experimental Evidence (5 terms)
CV Term
Evidence
References
involved_in establishment of glial blood-brain barrier
inferred from mutant phenotype
(Stork et al., 2008)
involved_in liquid clearance, open tracheal system
inferred from mutant phenotype
(Jaspers et al., 2012)
involved_in open tracheal system development
inferred from mutant phenotype
(Behr et al., 2003, Beitel and Krasnow, 2000)
involved_in regulation of tube size, open tracheal system
inferred from mutant phenotype
(Beitel and Krasnow, 2000)
involved_in septate junction assembly
inferred from mutant phenotype
(Behr et al., 2003)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
involved_in regulation of tube size, open tracheal system
inferred from biological aspect of ancestor with PANTHER:PTN001083506
(GO Reference Genome Project, 2011-)
involved_in septate junction assembly
inferred from biological aspect of ancestor with PANTHER:PTN001083506
(GO Reference Genome Project, 2011-)
Cellular Component (2 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
located_in septate junction
inferred from direct assay
(Jaspers et al., 2012)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
located_in membrane
inferred from sequence model
(Jaspers et al., 2012)
inferred from electronic annotation with InterPro:IPR004031
(InterPro Project Members, 2004-)
is_active_in septate junction
inferred from biological aspect of ancestor with PANTHER:PTN001083506
(GO Reference Genome Project, 2011-)
located_in septate junction
inferred from sequence or structural similarity with FLYBASE:sinu; FB:FBgn0010894
(Wu et al., 2004)
Gene Group (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
Summaries
Gene Snapshot
pickel (pck) encodes a transmembrane protein of the Claudin superfamily. It is part of the septate junction (SJ) core complex and essential for SJ morphogenesis and function. The transepithelial barrier function of epithelial tissues is affected in pck mutants. [Date last reviewed: 2019-03-14]
Summary (Interactive Fly)

megatrachea claudin required for septate junction formation and barrier function - control of secretion processes specific to septate junction and dependent on Sec61p may involve Megatrachea interaction with Sec61 subunits, trachea

Gene Model and Products
Number of Transcripts
3
Number of Unique Polypeptides
2

Please see the JBrowse view of Dmel\pck 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 O76899)

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 5.49

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
pck-RA
FBtr0070255
NM_166887
1399
256
pck-RC
FBtr0070256
NM_130563
1289
256
pck-RD
FBtr0100198
NM_001038731
1360
136
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
pck-PA
FBpp0070245
29.8
256
8.64
O76899
NP_726742
AAF45632
pck-PC
FBpp0070246
29.8
256
8.64
O76899
NP_569919
AAG22385
pck-PD
FBpp0099568
15.6
136
8.36
Q2PE37
NP_001033820
ABC67163
Polypeptides with Identical Sequences

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

256 aa isoforms: pck-PA, pck-PC
Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
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\pck 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).

0.03

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage 1 -- 3
organism

Comment: maternally deposited

(Fisher et al., 2012)
embryonic stage 4 -- 6
organism
(Fisher et al., 2012)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in septate junction
inferred from direct assay
(Jaspers et al., 2012)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\pck 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
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 7 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 11 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of pck
Transgenic constructs containing regulatory region of pck
Aberrations (Deficiencies and Duplications) ( 22 )
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
lethal, with Dcr-2UAS.cDa, Scer\GAL4elav.PLu
lethal | recessive
lethal - all die during embryonic stage
lethal - all die during embryonic stage, with Dcr-2UAS.cDa, Scer\GAL4elav.PLu
lethal - all die during embryonic stage | recessive
viable
Other Phenotypes
Allele
some die during embryonic stage
some die during embryonic stage | recessive
Phenotype manifest in
Allele
abdominal 1 ventral denticle belt
abdominal 2 ventral denticle belt
abdominal 3 ventral denticle belt
abdominal 4 ventral denticle belt
abdominal 5 ventral denticle belt
abdominal 6 ventral denticle belt
abdominal 7 ventral denticle belt
apical plasma membrane | embryonic stage
cuticle
embryonic/larval tracheal dorsal trunk
embryonic/larval tracheal dorsal trunk | embryonic stage
embryonic/larval tracheal section
embryonic/larval tracheal section | embryonic stage
embryonic/larval tracheal transverse connective
embryonic dorsal trunk & cell
epidermal cell | embryonic stage
larval tracheal system
larval tracheocyte | embryonic stage
pleated septate junction & tracheal system
septate junction | embryonic stage
tracheal dorsal trunk primordium
tracheal dorsal trunk primordium | embryonic stage
tracheal dorsal trunk primordium | embryonic stage 14
tracheal section
tracheal section | embryonic stage
tracheal transverse connective primordium
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\LIM2
1 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\Lim2
1 of 14
Yes
Yes
Mus musculus (laboratory mouse) (0)
Xenopus tropicalis (Western clawed frog) (3)
Xtro\lim2
1 of 13
Yes
Yes
Xtro\LOC100487261
1 of 13
Yes
Yes
Xtro\LOC101731523
1 of 13
Yes
Yes
Danio rerio (Zebrafish) (2)
Drer\lim2.4
1 of 14
Yes
Yes
Drer\lim2.5
1 of 14
Yes
Yes
Caenorhabditis elegans (Nematode, roundworm) (0)
Anopheles gambiae (African malaria mosquito) (3)
Agam\AgaP_AGAP003808
11 of 12
Yes
Yes
Agam\AgaP_AGAP003810
2 of 12
No
No
Agam\AgaP_AGAP003809
1 of 12
No
No
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:pck. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Gene Symbol
Score
Source
Compara
Domainoid
eggNOG
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Drosophila melanogaster (Fruit fly) (3)
kune
4 of 13
sinu
3 of 13
Tmhs
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 ( 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
    Summary of Genetic Interactions
    Interaction Browsers
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    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)
    X
    Recombination map
    1-0.2
    Cytogenetic map
    2A4-2A4
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    2A4-2A4
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    2A1-2A2
    (determined by in situ hybridization) 2B1--4 (determined by in situ hybridization)
    (Peter et al., 2002, Schäfer et al., 1999.6.15)
    2B1-2B4
    (determined by in situ hybridization) 2A3--B2 (determined by in situ hybridization)
    (Schäfer et al., 1999.8.12)
    Location 2B1--4 inferred from insertion in: pckG0012
    (Schäfer et al., 1999.8.12)
    Experimentally Determined Recombination Data
    Location

    1-0.2

    (FlyBase, 2016)

    1-0.1

    (Comeron et al., 2012)
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (10)
    Genomic Clones (8)
     

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

    cDNA Clones (58)
     

    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
       

      monoclonal

      (Jaspers et al., 2012)
      Commercially Available Antibodies
       
      Cell Line Information
      Publicly Available Cell Lines
       
        Other Stable Cell Lines
         
          Other Comments

          Proper targetting of pck gene product to the pleated septate junctions in the tracheal system depends on Nrx-IV and cora but not Fas3.

          (Behr et al., 2003)

          Maternal expression of pck is not essential for normal development or viability.

          (Behr et al., 2003)

          Mutation in pck alters tracheal tube size in embryos without affecting other aspects of tracheal development including primary branch budding and outgrowth or branch fusion.

          (Beitel and Krasnow, 2000)
          Relationship to Other Genes
          Source for database merge of

          Source for merge of: pck l(1)G0012

          (Wu et al., 2004)

          Source for merge of: l(1)G0012 CG14779 l(1)G0044

          (Peter et al., 2002)
          Additional comments
          Nomenclature History
          Source for database identify of

          Source for identity of: pck mega

          (Beitel and Krasnow, 2000)
          Nomenclature comments
          Etymology
          Synonyms and Secondary IDs (12)
          Reported As
          Symbol Synonym
          CG14779
          (Jaspers et al., 2012, Metta and Schlötterer, 2010, Ni et al., 2010.12.1, Wu et al., 2004)
          EG:80H7.2
          (Giot et al., 2003, Peter et al., 2002, Benos et al., 2001, Benos, 2000.12.13)
          Mega
          (Göpfert et al., 2025, Pannen et al., 2020, Skouloudaki et al., 2019, Jaspers et al., 2014, Laprise et al., 2010, Harder et al., 2008, Kertesz et al., 2007, Furuse and Tsukita, 2006, Behr et al., 2005, Jane et al., 2005)
          PCK
          (Bassett et al., 2014)
          Pck
          (Caussinus et al., 2011)
          l(1)G0044
          (Peter et al., 2002, Schäfer et al., 1999.6.15, Schäfer et al., 1999.8.12)
          mega
          (Drees et al., 2023, Behr and Riedel, 2020, Königsmann et al., 2020, Drees et al., 2019, Tempesta et al., 2017, Hildebrandt et al., 2015, Bätz et al., 2014, Jaspers et al., 2012, Nelson et al., 2010, Harder et al., 2008, Luschnig et al., 2006, Moussian et al., 2006, Tonning et al., 2005, Anderson et al., 2004, Wu and Beitel, 2004, Wu et al., 2004, Behr et al., 2003, Paul et al., 2003, Behr and Schuh, 2002, Beitel and Krasnow, 2000)
          pck
          (Adashev et al., 2022, Rouka et al., 2021, Graves et al., 2020, Sarov et al., 2016, Hall et al., 2014, Yamamoto et al., 2013-, Hong et al., 2009, Iovino et al., 2009, Stork et al., 2008, Tonning et al., 2005)
          Name Synonyms
          Megatrachea
          (Göpfert et al., 2025, Markovich et al., 2024, Buckley and St Johnston, 2022, Lim et al., 2019, Yeh et al., 2018, Leiserson and Keshishian, 2011, Rodrigues et al., 2011, Laprise et al., 2010, Nelson et al., 2010, Harder et al., 2008)
          Pickel
          (Rice et al., 2021)
          megatrachea
          (Stork et al., 2008, Furuse and Tsukita, 2006, Luschnig et al., 2006, Anderson et al., 2004, Wu and Beitel, 2004, Paul et al., 2003, Paul et al., 2003, Beitel and Krasnow, 2000)
          pickel
          (Graves et al., 2020, Jaspers et al., 2012, Degelmann, 1993)
          Secondary FlyBase IDs
          • FBgn0001369
          • FBgn0025384
          • FBgn0027323
          • FBgn0027333
          Datasets (0)
          Study focus (0)
          Experimental Role
          Project
          Project Type
          Title
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 44 )
          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/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
          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 (84)