FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\papi
Open Close
General Information
Symbol
Dmel\papi
Species
D. melanogaster
Name
papi
Annotation Symbol
CG7082
Feature Type
FlyBase ID
FBgn0031401
Gene Model Status
Stock Availability
Gene Summary
Involved in the piwi-interacting RNA (piRNA) metabolic process, which mediates the repression of transposable elements during meiosis by forming complexes composed of piRNAs and Piwi proteins, and governs the methylation and subsequent repression of transposons which is essential for germline integrity (PubMed:21447556, PubMed:29531043). Likely to act by recruiting Piwi proteins such as AGO3 and piwi to the piRNA biogenesis machinery in the nuage (PubMed:21447556, PubMed:29531043). Required for the final steps of primary piRNA biogenesis by participating in the 3' end-trimming of piwi-bound intermediates into mature piRNAs (PubMed:29531043). (UniProt, Q9VQ91)
Contribute a Gene Snapshot for this gene.
Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
2-5
RefSeq locus
NT_033779 REGION:2220748..2225544
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 (1 term)
CV Term
Evidence
References
inferred from physical interaction with FLYBASE:me31B; FB:FBgn0004419
inferred from physical interaction with FLYBASE:tral; FB:FBgn0041775
inferred from physical interaction with FLYBASE:TER94; FB:FBgn0286784
inferred from physical interaction with UniProtKB:Q9VKM1
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from electronic annotation with InterPro:IPR004087
enables RNA binding
inferred from electronic annotation with InterPro:IPR004088, InterPro:IPR036612
Biological Process (5 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
involved_in piRNA processing
inferred from mutant phenotype
inferred from physical interaction with FLYBASE:piwi; FB:FBgn0004872
inferred from mutant phenotype
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN002741755
involved_in piRNA processing
inferred from biological aspect of ancestor with PANTHER:PTN002741755
involved_in spermatogenesis
inferred from biological aspect of ancestor with PANTHER:PTN002741755
Cellular Component (3 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
is_active_in mitochondrion
inferred from direct assay
located_in P granule
inferred from direct assay
inferred from direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
is_active_in P granule
inferred from biological aspect of ancestor with PANTHER:PTN002741755
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the Tdrkh family. (Q9VQ91)
Summaries
Protein Function (UniProtKB)
Involved in the piwi-interacting RNA (piRNA) metabolic process, which mediates the repression of transposable elements during meiosis by forming complexes composed of piRNAs and Piwi proteins, and governs the methylation and subsequent repression of transposons which is essential for germline integrity (PubMed:21447556, PubMed:29531043). Likely to act by recruiting Piwi proteins such as AGO3 and piwi to the piRNA biogenesis machinery in the nuage (PubMed:21447556, PubMed:29531043). Required for the final steps of primary piRNA biogenesis by participating in the 3' end-trimming of piwi-bound intermediates into mature piRNAs (PubMed:29531043).
(UniProt, Q9VQ91)
Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\papi 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 Q9VQ91)

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

Annotated transcripts do not represent all supported alternative splices within 5' UTR.

Gene model reviewed during 5.44

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

Gene model reviewed during 5.47

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0077836
2325
576
FBtr0077838
2235
576
FBtr0077837
2331
576
FBtr0077839
2112
576
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
FBpp0077508
63.8
576
6.22
FBpp0077510
63.8
576
6.22
FBpp0077509
63.8
576
6.22
FBpp0077511
63.8
576
6.22
Polypeptides with Identical Sequences

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

576 aa isoforms: papi-PA, papi-PB, papi-PC, papi-PD
Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Subunit Structure (UniProtKB)

Interacts (via C-terminus) with AGO3 (via the N-terminal region when symmetrically methylated on arginine residues); this interaction is RNA-independent and may be required for AGO3 localization to the nuage (PubMed:21447556). Interacts (via Tudor domain) with piwi (via N-terminus) (PubMed:21447556, PubMed:29531043). Interacts with tral and me31B (PubMed:21447556).

(UniProt, Q9VQ91)
Domain

The Tudor domain is sufficient for binding to the N-terminus (1-14) of both unmethylated piwi or piwi symmetrically dimethylated at 'Arg-10' (PubMed:29531043). However, it may not be sufficient for binding to symmetrically dimethylated AGO3, instead this interaction may require a larger region of the C-terminus which includes the Tudor domain (257-576) (PubMed:21447556, PubMed:29531043).

(UniProt, Q9VQ91)
Crossreferences
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\papi 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).

4.14

Transcript Expression
Polypeptide Expression
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

In adult fly ovaries papi is predominantly present in the the cytoplasm of both germarium cells and somatic follicle cells. It is present in germline stem cells and germline cyst cells, as well as in nurse cells and oocytes with a strong accumulation in region IIb germline cysts in the germarium. In post-germarial egg chambers, papi accumulates in perinuclear loci that appear to be the nuage. In early embryos, papi is the cytoplasm throughout the whole embryo, including the pole cells. No specific localization was observed in embryos. Colocalization of papi with AGO3 was seen, particularly in the cytoplasm of germline stem cells, differentiating cysts, and postgermarial egg chambers. It is particularly pronounced in the nuage of nurse cells. In early embryos, they colocalize in the cytoplasm.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
is_active_in mitochondrion
inferred from direct assay
located_in P granule
inferred from direct assay
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\papi 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) 11-12
  • Stages(s) 13-16
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 20 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 18 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of papi
Transgenic constructs containing regulatory region of papi
Aberrations (Deficiencies and Duplications) ( 2 )
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
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) (15)
12 of 14
Yes
Yes
3 of 14
No
No
1  
2 of 14
No
No
2 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1  
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
1 of 14
No
No
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) (12)
12 of 14
Yes
Yes
3 of 14
No
No
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
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (13)
11 of 14
Yes
Yes
3 of 14
No
No
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
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) (10)
10 of 13
Yes
Yes
2 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
Yes
1 of 13
No
No
Danio rerio (Zebrafish) (15)
13 of 14
Yes
Yes
3 of 14
No
No
2 of 14
No
No
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
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (5)
1 of 14
Yes
No
1 of 14
Yes
Yes
1 of 14
Yes
Yes
1 of 14
Yes
No
1 of 14
Yes
Yes
Anopheles gambiae (African malaria mosquito) (9)
11 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (4)
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
Saccharomyces cerevisiae (Brewer's yeast) (0)
Schizosaccharomyces pombe (Fission yeast) (1)
1 of 12
Yes
No
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:papi. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (11)
3 of 13
3 of 13
2 of 13
2 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 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 ( 1 )
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
Subunit Structure (UniProtKB)
Interacts (via C-terminus) with AGO3 (via the N-terminal region when symmetrically methylated on arginine residues); this interaction is RNA-independent and may be required for AGO3 localization to the nuage (PubMed:21447556). Interacts (via Tudor domain) with piwi (via N-terminus) (PubMed:21447556, PubMed:29531043). Interacts with tral and me31B (PubMed:21447556).
(UniProt, Q9VQ91 )
Linkouts
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)
2L
Recombination map
2-5
Cytogenetic map
Sequence location
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
22D4-22D4
Limits computationally determined from genome sequence between P{lacW}s4989 and P{lacW}Rab5k08232
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
Experimentally Determined Recombination Data
Location
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (20)
Genomic Clones (15)
 

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

cDNA Clones (40)
 

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

      papi interacts most strongly with piwi, strongly with AGO3 and weakly with aub, but fails to interact with AGO1 and AGO2.

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

      Source for identity of: papi CG7082

      Nomenclature comments
      Etymology
      Synonyms and Secondary IDs (6)
      Datasets (0)
      Study focus (0)
      Experimental Role
      Project
      Project Type
      Title
      Study result (0)
      Result
      Result Type
      Title
      External Crossreferences and Linkouts ( 68 )
      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
      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
      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
      FlyMet - A comprehensive tissue-specific metabolomics resource for Drosophila.
      iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
      MIST (protein-protein) - An integrated Molecular Interaction Database
      References (62)