FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\krimp
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General Information
Symbol
Dmel\krimp
Species
D. melanogaster
Name
krimper
Annotation Symbol
CG15707
Feature Type
FlyBase ID
FBgn0034098
Gene Model Status
Stock Availability
Gene Summary
Stable structural component of the perinuclear meiotic nuage, a germline-specific subcellular membraneless ribonucleoprotein compartment involved in production of transposable element-repressing Piwi-interacting RNA (piRNA)-induced silencing complexes (piRISCs), which are essential for maintaining germline integrity during oogenesis (PubMed:17428915, PubMed:26212455, PubMed:26295961). Scaffold component of the ping-pong piRNA processing (4P) complex that recruits the Piwi proteins aub and AGO3 to specific subregions of the nuage where it coordinates their activity in the ping-pong amplification step of secondary piRNA biogenesis (PubMed:26295961, PubMed:34210982). Binds methylated aub, which is associated with piRNA, and unmethylated AGO3, which is not associated with piRNA, bringing the Piwi proteins into close proximity and facilitating the loading of freshly cut piRNAs generated by aub onto AGO3 (PubMed:34210982). Promotes asymmetric ping-pong amplification by aub and AGO3 to bias production towards antisense piRNAs capable of silencing transposable elements (PubMed:26212455). Required for symmetrical dimethylation of AGO3, probably by recruitment to the nuage where methylosome components are located; dimethylation promotes AGO3 dissociation and interaction with other tudor-domain containing proteins such as tud (PubMed:26212455). Required for the recruitment of mael to the perinuclear meiotic nuage (PubMed:17428915). Required for the recruitment of aub to the nuage in testes but not in ovaries (PubMed:22303351). Involved in repression of long interspersed nuclear elements (LINEs) including HeT-A, I-element LINEs and possibly mst40, but not TART LINEs (PubMed:17428915). (UniProt, A1ZAC4)
Contribute a Gene Snapshot for this gene.
Also Known As

montecristo, mtc

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
2-79
RefSeq locus
NT_033778 REGION:16238103..16240722
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (8 terms)
Molecular Function (1 term)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from electronic annotation with InterPro:IPR000571
Biological Process (5 terms)
Terms Based on Experimental Evidence (5 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from physical interaction with FLYBASE:aub; FB:FBgn0000146,FLYBASE:AGO3; FB:FBgn0250816
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
is_active_in P granule
located_in P granule
inferred from direct assay
inferred from direct assay
Terms Based on Predictions or Assertions (0 terms)
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the Tudor domain containing protein family. (A1ZAC4)
Summaries
Protein Function (UniProtKB)
Stable structural component of the perinuclear meiotic nuage, a germline-specific subcellular membraneless ribonucleoprotein compartment involved in production of transposable element-repressing Piwi-interacting RNA (piRNA)-induced silencing complexes (piRISCs), which are essential for maintaining germline integrity during oogenesis (PubMed:17428915, PubMed:26212455, PubMed:26295961). Scaffold component of the ping-pong piRNA processing (4P) complex that recruits the Piwi proteins aub and AGO3 to specific subregions of the nuage where it coordinates their activity in the ping-pong amplification step of secondary piRNA biogenesis (PubMed:26295961, PubMed:34210982). Binds methylated aub, which is associated with piRNA, and unmethylated AGO3, which is not associated with piRNA, bringing the Piwi proteins into close proximity and facilitating the loading of freshly cut piRNAs generated by aub onto AGO3 (PubMed:34210982). Promotes asymmetric ping-pong amplification by aub and AGO3 to bias production towards antisense piRNAs capable of silencing transposable elements (PubMed:26212455). Required for symmetrical dimethylation of AGO3, probably by recruitment to the nuage where methylosome components are located; dimethylation promotes AGO3 dissociation and interaction with other tudor-domain containing proteins such as tud (PubMed:26212455). Required for the recruitment of mael to the perinuclear meiotic nuage (PubMed:17428915). Required for the recruitment of aub to the nuage in testes but not in ovaries (PubMed:22303351). Involved in repression of long interspersed nuclear elements (LINEs) including HeT-A, I-element LINEs and possibly mst40, but not TART LINEs (PubMed:17428915).
(UniProt, A1ZAC4)
Summary (Interactive Fly)

a component of nuage in the germline that functions to repress selfish genetic elements - Aub and Ago3 are recruited to nuage to form a ping-pong complex assembled by Krimper - simultaneously binds the N-terminal regions of Aub and Ago3 to promote generation of new piRNA - Krimper enforces an antisense bias on piRNA pools by binding AGO3 in the Drosophila germline

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

Please see the JBrowse view of Dmel\krimp 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 A1ZAC4)

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

Gene model reviewed during 5.50

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0087189
2549
746
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
FBpp0086333
84.0
746
5.16
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)
Comments
External Data
Subunit Structure (UniProtKB)

Homooligomerizes (via N-terminus) (PubMed:26295961). Component of the ping-pong piRNA processing (4P) complex consisting of krimp, aub and AGO3; a single molecule of krimp can bind both aub and AGO3 without the need for homooligomerization (PubMed:26295961, PubMed:34210982). Interacts (via canonical tudor domain) with aub (via N-terminus when symmetrically dimethylated on arginine residues) (PubMed:26295961, PubMed:34210982). Interacts (via non-canonical tudor domain) with AGO3 (via N-terminus when unmethylated on arginine residues); this interaction leads to symmetrical dimethylation on AGO3 arginine residues and its subsequent dissociation from krimp (PubMed:26212455, PubMed:26295961, PubMed:34210982). Krimp associated AGO3 is mostly free of piRNA binding and the interaction plays an important role in the loading of AGO3 with piRNAs; piRNA binding stimulates methylation of ACO3 by the csul/PRMT5 methylosome complex and promotes dissociation of the two proteins (PubMed:26212455, PubMed:26295961, PubMed:34210982).

(UniProt, A1ZAC4)
Domain

Possesses two tudor domains, a C-terminal canonical tudor domain and a central non-canonical tudor domain (Probable) (PubMed:34210982). Both tudor domains can interact with Piwi proteins allowing the simultaneous binding of aub and AGO3; this brings them in close proximity to facilitate their role in ping-pong ampification of piRNAs (PubMed:26295961, PubMed:34210982). The canonical tudor domain possesses a hydrophobic pocket that preferentially binds methylated aub; the interaction requires symmetrical methylation on at least one aub N-terminal arginine (PubMed:26295961, PubMed:34210982). The non-canonical tudor domain possesses a hydrophilic binding pocket that preferentially binds unmethylated AGO3; methylation on any of the AGO3 N-terminal arginines disrupts this interaction (PubMed:34210982). The differential binding preference ensures recruitment of one piRNA loaded (aub) and one unloaded (AGO3) Piwi-protein; the methylation state of the Piwi proteins acts as an indicator of their piRNA binding state (PubMed:34210982).

(UniProt, A1ZAC4)
Crossreferences
PDB - An information portal to biological macromolecular structures
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\krimp 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).

-0.09

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
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
is_active_in P granule
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\krimp 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 ( 6 )
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 krimp
Transgenic constructs containing regulatory region of krimp
Aberrations (Deficiencies and Duplications) ( 1 )
Inferred from experimentation ( 1 )
Inferred from location ( 8 )
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) (7)
3 of 14
Yes
No
3 of 14
Yes
No
2 of 14
No
No
2 of 14
No
No
2 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) (7)
3 of 14
Yes
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
Mus musculus (laboratory mouse) (6)
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
1 of 14
No
No
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (6)
2 of 13
Yes
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
Danio rerio (Zebrafish) (9)
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (2)
1 of 14
Yes
Yes
1 of 14
Yes
No
Anopheles gambiae (African malaria mosquito) (10)
6 of 12
Yes
Yes
1 of 12
No
No
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) (1)
1 of 13
Yes
No
Schizosaccharomyces pombe (Fission yeast) (2)
1 of 12
Yes
No
1 of 12
Yes
No
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:krimp. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (10)
4 of 13
2 of 13
2 of 13
2 of 13
2 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 ( 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
    Subunit Structure (UniProtKB)
    Homooligomerizes (via N-terminus) (PubMed:26295961). Component of the ping-pong piRNA processing (4P) complex consisting of krimp, aub and AGO3; a single molecule of krimp can bind both aub and AGO3 without the need for homooligomerization (PubMed:26295961, PubMed:34210982). Interacts (via canonical tudor domain) with aub (via N-terminus when symmetrically dimethylated on arginine residues) (PubMed:26295961, PubMed:34210982). Interacts (via non-canonical tudor domain) with AGO3 (via N-terminus when unmethylated on arginine residues); this interaction leads to symmetrical dimethylation on AGO3 arginine residues and its subsequent dissociation from krimp (PubMed:26212455, PubMed:26295961, PubMed:34210982). Krimp associated AGO3 is mostly free of piRNA binding and the interaction plays an important role in the loading of AGO3 with piRNAs; piRNA binding stimulates methylation of ACO3 by the csul/PRMT5 methylosome complex and promotes dissociation of the two proteins (PubMed:26212455, PubMed:26295961, PubMed:34210982).
    (UniProt, A1ZAC4 )
    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)
    2R
    Recombination map
    2-79
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    53A1-53A1
    Limits computationally determined from genome sequence between P{lacW}Lis-1k11702&P{EP}CG8443EP969 and P{lacW}l(2)k07824k07824&P{lacW}vegk03402
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (8)
    Genomic Clones (13)
     

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

    cDNA Clones (25)
     

    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
    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

        mtc is required for meiotic progression.

        mtc mutants show a delay in the restriction of the synaptonemal complex and cause abnormal karyosome morphology in the later stages of oogenesis.

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

        Source for identity of: mtc CG15707

        Source for identity of: krimp CG15707

        Nomenclature comments
        Etymology

        The gene is named "montecristo", after a brand of Cuban cigars, due to the mutant eggshell phenotype.

        Synonyms and Secondary IDs (9)
        Reported As
        Secondary FlyBase IDs
          Datasets (0)
          Study focus (0)
          Experimental Role
          Project
          Project Type
          Title
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 43 )
          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.
          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
          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.
          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
          Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
          MIST (protein-protein) - An integrated Molecular Interaction Database
          References (106)