FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\modSP
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General Information
Symbol
Dmel\modSP
Species
D. melanogaster
Name
modular serine protease
Annotation Symbol
CG31217
Feature Type
FlyBase ID
FBgn0051217
Gene Model Status
Stock Availability
Enzyme Name (EC)
Gene Summary
modular serine protease (modSP) encodes a protein that functions downstream of microbial sensing receptors encoded by PGRP-SA and GNBP3 in the extracellular proteolytic cascade leading to Toll pathway activation during the immune response. It initiates the proteolytic cascade leading to the cleavage of the Toll ligand encoded by spz. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
Also Known As

W, X, Ser89E, SP53

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
3-59
RefSeq locus
NT_033777 REGION:16652446..16655662
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (9 terms)
Molecular Function (1 term)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
Biological Process (7 terms)
Terms Based on Experimental Evidence (6 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000667087
involved_in proteolysis
inferred from sequence model
inferred from electronic annotation with InterPro:IPR001254, InterPro:IPR018114
Cellular Component (1 term)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
is_active_in extracellular space
inferred from biological aspect of ancestor with PANTHER:PTN000667087
Protein Family (UniProt)
Belongs to the peptidase S1 family. (Q9VER6)
Catalytic Activity (EC/Rhea)
serine-type endopeptidase activity
Summaries
Gene Snapshot
modular serine protease (modSP) encodes a protein that functions downstream of microbial sensing receptors encoded by PGRP-SA and GNBP3 in the extracellular proteolytic cascade leading to Toll pathway activation during the immune response. It initiates the proteolytic cascade leading to the cleavage of the Toll ligand encoded by spz. [Date last reviewed: 2019-03-14]
Pathway (FlyBase)
EXTRACELLULAR SPATZLE ACTIVATING PATHWAY CORE COMPONENTS -
In Drosophila, activation of the Toll pathway is controlled by the generation of a cleaved, active, Toll-binding form of spatzle ligand. Proteolytic activation of spatzle ligand lies downstream of several zymogen activation cascades that are initiated by different cues. In dorsal-ventral patterning, localized activation of spz results in ventral nuclear accumulation of dl. During viral and fungal and gram positive bacterial immune challenge, zymogen cascades are activated by extracellular pattern recognition receptors or virulence factor-mediated cleavage of the zymogen persephone (psh). (Adapted from FBrf0091014 and FBrf0223077).
Gene Group (FlyBase)
S1A SERINE PROTEASES - CHYMOTRYPSIN-LIKE -
Chymotrypsin-like serine proteases cleave substrates following one of the hydrophobic amino acids at the P1 position. (Adapted from FBrf0239469). Chymotrypsin-like serine proteases of the S1A family are endopeptidases that cleave substrates following one of the hydrophobic amino acids at the P1 position. (Adapted from FBrf0239469).
Protein Function (UniProtKB)
Serine protease that plays a key role in innate immunity by activating the Toll pathway in response to infection with Gram-positive bacteria and fungi (PubMed:19590012, PubMed:24794300). During Gram-positive infection, acts downstream of PGRP-SA and upstream of Grass and Spz, and therefore appears to function in a pathway that links detection of Gram-positive lysine-type peptidoglycans to Toll activation (PubMed:19590012). Functions in a separate pathway to the psh-mediated activation of the Toll pathway (PubMed:19590012).
(UniProt, Q9VER6)
Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\modSP 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 Q9VER6)

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 5.47

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0083353
2289
628
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
FBpp0082798
69.4
628
5.40
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
Post Translational Modification

May be proteolytically cleaved via an autocatalytic mechanism.

(UniProt, Q9VER6)
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\modSP 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).

-0.79

Transcript Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\modSP 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
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 ( 5 )
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 modSP
Transgenic constructs containing regulatory region of modSP
Aberrations (Deficiencies and Duplications) ( 3 )
Inferred from experimentation ( 3 )
Inferred from location ( 5 )
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) (50)
2 of 14
Yes
Yes
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Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (21)
2 of 14
Yes
Yes
1 of 14
No
Yes
1 of 14
No
Yes
1 of 14
No
No
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No
No
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Yes
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Yes
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1 of 14
No
No
Mus musculus (laboratory mouse) (24)
1 of 14
Yes
Yes
1 of 14
Yes
Yes
1 of 14
Yes
No
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No
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No
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No
1 of 14
Yes
No
Xenopus tropicalis (Western clawed frog) (39)
2 of 13
Yes
Yes
1 of 13
No
No
1 of 13
No
No
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No
No
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No
No
1 of 13
No
Yes
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No
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No
No
1 of 13
No
No
Danio rerio (Zebrafish) (32)
2 of 14
Yes
Yes
2 of 14
Yes
Yes
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
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No
1 of 14
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Yes
1 of 14
No
Yes
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) (19)
2 of 14
Yes
No
2 of 14
Yes
Yes
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
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No
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1 of 14
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Yes
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Yes
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
Anopheles gambiae (African malaria mosquito) (91)
9 of 12
Yes
Yes
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
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No
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No
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No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
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:modSP. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (147)
3 of 13
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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

    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
    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
    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)
    3R
    Recombination map
    3-59
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    89D6-89D6
    Limits computationally determined from genome sequence between P{lacW}CSN5L4032 and P{EP}MESK4EP1015
    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 (16)
     

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

    cDNA Clones (27)
     

    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

          modSP is required for Tl pathway activity in a step downstream of the recognition of lysine-type peptidoglycan.

          modSP is involved in the activation of the Tl pathway by Gram-positive bacteria.

          Epistatic analysis indicates that modSP functions downstream of PGRP-SA and GNBP1 and upstream of grass in the pathway that links Gram-positive bacterial recognition to Tl activation.

          Identified as one of 10 highest fold cycling genes as assessed by expression analysis using high density oligonucleotide arrays with probe generated from adult heads harvested over six time points over the course of a day.

          The complete sequence of the bithorax complex is available.

          Relationship to Other Genes
          Source for database merge of
          Additional comments

          Annotations CG17557, CG10100 merged as CG31217 in release 3 of the genome annotation.

          Nomenclature History
          Source for database identify of

          Source for identity of: modSP CG31217

          Nomenclature comments
          Etymology
          Synonyms and Secondary IDs (21)
          Reported As
          Symbol Synonym
          CG10100
          CG17557
          Ldlr
          Name Synonyms
          Serine protease like 89E
          Serine protease-like
          low density lipoprotein receptor-like 'a' repeats
          predicted gene W
          predicted gene X
          Secondary FlyBase IDs
          • FBgn0013291
          • FBgn0015294
          Datasets (0)
          Study focus (0)
          Experimental Role
          Project
          Project Type
          Title
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 48 )
          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)
          MEROPS - An information resource for peptidases (also termed proteases, proteinases and proteolytic enzymes) and the proteins that inhibit them.
          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
          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 (protein-protein) - An integrated Molecular Interaction Database
          References (87)