FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\sfl
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General Information
Symbol
Dmel\sfl
Species
D. melanogaster
Name
sulfateless
Annotation Symbol
CG8339
Feature Type
FlyBase ID
FBgn0020251
Gene Model Status
Stock Availability
Enzyme Name (EC)
[heparan sulfate]-glucosamine N-sulfotransferase (2.8.2.8)
Gene Summary
sulfateless sfl encodes a heparan sulfate-glucosamine N-sulfotransferase that catalyzes both the N-deacetylation and the N-sulfation of N-acetyl-glucosamine (GlcNAc) of the heparan sulfate glycosaminoglycan chain. It is involved in the first step in heparan sulfate modification and is required for subsequent sulfotransferase reactions at the 2-O position of iduronate or glucuronate, and the 6-O-position of glucosamine. [Date last reviewed: 2024-12-19] (FlyBase Gene Snapshot)
Also Known As

NDST, lincRNA.S4253

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
3-17
RefSeq locus
NT_037436 REGION:6495680..6550104
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (20 terms)
Molecular Function (5 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (5 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000834543
inferred from sequence or structural similarity with UniProtKB:O95803
inferred from electronic annotation with InterPro:IPR021930
inferred from biological aspect of ancestor with PANTHER:PTN000834543
inferred from electronic annotation with InterPro:IPR021930
Biological Process (12 terms)
Terms Based on Experimental Evidence (12 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from genetic interaction with UniProtKB:Q09147
inferred from mutant phenotype
inferred from genetic interaction with UniProtKB:Q07407
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
involved_in spermatogenesis
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
Cellular Component (3 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
is_active_in Golgi apparatus
inferred from biological aspect of ancestor with PANTHER:PTN000834543
Protein Family (UniProt)
Belongs to the sulfotransferase 1 family. NDST subfamily. (Q9V3L1)
Catalytic Activity (EC/Rhea)
heparan sulfate N-sulfotransferase activity
alpha-D-glucosaminyl-[heparan sulfate](n) + 3'-phosphoadenylyl sulfate = N-sulfo-alpha-D-glucosaminyl-[heparan sulfate](n) + adenosine 3',5'-bisphosphate + 2 H(+) (2.8.2.8)
RHEA 21980: heparan sulfate N-deacetylase activity
RHEA 70587:
Summaries
Gene Snapshot
sulfateless sfl encodes a heparan sulfate-glucosamine N-sulfotransferase that catalyzes both the N-deacetylation and the N-sulfation of N-acetyl-glucosamine (GlcNAc) of the heparan sulfate glycosaminoglycan chain. It is involved in the first step in heparan sulfate modification and is required for subsequent sulfotransferase reactions at the 2-O position of iduronate or glucuronate, and the 6-O-position of glucosamine. [Date last reviewed: 2024-12-19]
Gene Group (FlyBase)
HEPARAN SULFATE SULFOTRANSFERASES -
Heparan sulfate sulfotransferases transfers the sulfo group from 3'-phosphoadenosine 5'-phosphosulfate on to heparan sulfate. (Adapted from FBrf0202009).
UNCLASSIFIED CARBOXYLIC ESTER HYDROLASES -
This group comprises carboxylic ester hydrolases that do not classify under other groups in FlyBase.
Pathway (FlyBase)
HEPARAN SULFATE PROTEOGLYCAN BIOSYNTHESIS -
Heparan sulfate proteoglycans (HSPGs) are glycoconjugates that consist of a core protein linked to one or more linear heparan sulfate (HS) chains. The chains are composed of alternating N-acetyl-D-glucosamine and glucuronic acid or iduronic acid that can be variably N- and O-sulfated. HS synthesis occurs in the Golgi apparatus. It starts with the formation of a tetrasaccharide linker on the core protein followed by the alternating addition of glucuronic acid and N-acetylglucosamine residues. Glucuronic acid can undergo epimerization into iduronic acid, which together with N-acetylglucosamine residues, can be sulfated. HSPGs are then transported to the plasma membrane where they can be processed further by endosulfatases such as Sulf1 that remove sulfate groups from specific sites. (Adapted from FBrf0232460 and FBrf0228609.)
Protein Function (UniProtKB)
Essential bifunctional enzyme that catalyzes both the N-deacetylation and the N-sulfation of glucosamine (GlcNAc) of the glycosaminoglycan in heparan sulfate. Modifies the GlcNAc-GlcA disaccharide repeating sugar backbone to make N-sulfated heparosan, a prerequisite substrate for later modifications in heparin biosynthesis. Plays a role in diffusion of morphogen wingless (wg) via its role in heparan sulfate proteoglycans (HSPGs) biosynthesis, HSPGs being required for movement of wg morphogens. Required for wg signaling during both embryonic and imaginal disk development. Also required for FGF receptor signaling.
(UniProt, Q9V3L1)
Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
3

Please see the JBrowse view of Dmel\sfl 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 Q9V3L1)

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 5.46

Gene model reviewed during 5.56

Double stop-codon suppression (UGA, UAG) postulated; FBrf0243886.

Gene model reviewed during 6.46

A subset of the transcripts annotated for this gene are postulated to be circular mRNAs (FBrf0246239).

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0076968
5772
1048
FBtr0301562
5735
1048
FBtr0481733
5735
1129
FBtr0481741
1071
199
Additional Transcript Data and Comments
Reported size (kB)

5.3 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0076677
118.6
1048
8.79
FBpp0290777
118.6
1048
8.79
FBpp0428487
127.7
1129
9.30
FBpp0428498
20.9
199
7.84
Polypeptides with Identical Sequences

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

1048 aa isoforms: sfl-PA, sfl-PB
Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Subunit Structure (UniProtKB)

Monomer.

(UniProt, Q9V3L1)
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\sfl 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).

-1.49

Transcript Expression
northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

sfl transcripts are detected in 0-1.5hr embryos on northern blots. Other stages were not tested.

Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
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\sfl 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
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 25 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 20 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of sfl
Transgenic constructs containing regulatory region of sfl
Aberrations (Deficiencies and Duplications) ( 1 )
Inferred from experimentation ( 1 )
Inferred from location ( 5 )
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
Other Phenotypes
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) (13)
13 of 14
Yes
Yes
1  
13 of 14
Yes
Yes
1  
12 of 14
No
Yes
12 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
1  
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
Yes
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)
13 of 14
Yes
Yes
12 of 14
No
Yes
12 of 14
No
Yes
12 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (12)
12 of 14
Yes
Yes
12 of 14
Yes
Yes
12 of 14
Yes
Yes
12 of 14
Yes
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
Yes
Xenopus tropicalis (Western clawed frog) (10)
10 of 13
Yes
Yes
10 of 13
Yes
Yes
8 of 13
No
Yes
7 of 13
No
Yes
6 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
Danio rerio (Zebrafish) (14)
12 of 14
Yes
Yes
11 of 14
No
Yes
11 of 14
No
Yes
11 of 14
No
Yes
11 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (3)
14 of 14
Yes
Yes
2 of 14
No
No
2 of 14
No
No
Anopheles gambiae (African malaria mosquito) (3)
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:sfl. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (2)
4 of 13
4 of 13
Human Disease Associations
FlyBase Human Disease Model Reports
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 4 )
Potential Models Based on Orthology ( 1 )
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.
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
suppressible
suppressible
Starting gene(s)
Interaction type
Interacting gene(s)
Reference
External Data
Subunit Structure (UniProtKB)
Monomer.
(UniProt, Q9V3L1 )
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
Pathways
Signaling Pathways (FlyBase)
Metabolic Pathways
External Links
KEGG Metabolic Pathways - A collection of manually drawn metabolic pathway maps representing knowledge of molecular interaction, reaction and relation networks.
Reactome Metabolic Pathways - An open-source, open access, manually curated and peer-reviewed metabolic pathway database.
External Data
Linkouts
KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
SignaLink - A signaling pathway resource with multi-layered regulatory networks.
Class of Gene
Genomic Location and Detailed Mapping Data
Chromosome (arm)
3L
Recombination map
3-17
Cytogenetic map
Sequence location
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
65B3-65B4
Limits computationally determined from genome sequence between P{PZ}l(3)0209402094 and P{lacW}l(3)L4060L4060
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
65C1-65C2
(determined by in situ hybridisation)
Experimentally Determined Recombination Data
Location
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (18)
Genomic Clones (47)
cDNA Clones (33)
 

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

        ChEST reveals this is a target of Mef2.

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

        Mutant clones do not show an alteration in the expression of intracellular wg protein but show a dramatic decrease in extracellular wg protein.

        sfl is essential for wg signalling.

        Loss of both maternal and zygotic sfl function results in profound defects in mesoderm and tracheal cell migration in the embryo.

        Identification: Defined by a P-element mutation.

        Cuticle phenotype similar to that of wg null alleles.

        The autosomal "FLP-DFS" technique (using the P{ovoD1-18} P{FRT(whs)} P{hsFLP} chromosomes) has been used to identify the specific maternal effect phenotype for the zygotic lethal mutation.

        Relationship to Other Genes
        Source for database merge of

        Source for merge of: sfl l(3)03844

        Additional comments

        Release 2 annotation CG8339 consisted of 2 non-overlapping transcripts - CT42364 and CT24567. These have been separated into 2 annotations in release 3 of the genome annotation; release 3 annotation CG32396 contains sequences corresponding to release 2 CT42364 and the release 3 annotation for sfl contains sequences corresponding to CT24567.

        Nomenclature History
        Source for database identify of

        Source for identity of: sfl CG8339

        Nomenclature comments
        Etymology
        Synonyms and Secondary IDs (15)
        Reported As
        Symbol Synonym
        l(3)03844
        Secondary FlyBase IDs
        • FBgn0010820
        Datasets (0)
        Study focus (0)
        Experimental Role
        Project
        Project Type
        Title
        Study result (0)
        Result
        Result Type
        Title
        External Crossreferences and Linkouts ( 57 )
        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)
        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
        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)
        KEGG Metabolic Pathways - A collection of manually drawn metabolic pathway maps representing knowledge of molecular interaction, reaction and relation networks.
        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
        Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
        Reactome Metabolic Pathways - An open-source, open access, manually curated and peer-reviewed metabolic pathway database.
        SignaLink - A signaling pathway resource with multi-layered regulatory networks.
        References (192)