FB2026_02 , released June 18, 2026
Gene: Dmel\sima
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General Information
Symbol
Dmel\sima
Species
D. melanogaster
Name
similar
Annotation Symbol
CG45051
Feature Type
FlyBase ID
FBgn0266411
Gene Model Status
Stock Availability
Gene Summary
Functions as a transcriptional regulator of the adaptive response to hypoxia. Binds to core DNA sequence 5'-[AG]CGTG-3' within the hypoxia response element (HRE) of target gene promoters. (UniProt, Q24167)
Contribute a Gene Snapshot for this gene.
Also Known As

HIF-1α, HIF-1a, HIF1α, HIF-1, HIFα

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
3-100
RefSeq locus
NT_033777 REGION:30058311..30121798
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (23 terms)
Molecular Function (4 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
Biological Process (15 terms)
Terms Based on Experimental Evidence (12 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from mutant phenotype
inferred from mutant phenotype
involved_in oogenesis
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
inferred from genetic interaction with FLYBASE:Vhl; FB:FBgn0041174
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
inferred from sequence or structural similarity with UniProtKB:Q16665
inferred from biological aspect of ancestor with PANTHER:PTN000548864
inferred from biological aspect of ancestor with PANTHER:PTN000548864
inferred from sequence or structural similarity with UniProtKB:Q16665
inferred from electronic annotation with InterPro:IPR013767
Cellular Component (4 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
is_active_in nucleus
inferred from biological aspect of ancestor with PANTHER:PTN008588220
inferred from biological aspect of ancestor with PANTHER:PTN000548864
Protein Family (UniProt)
-
Summaries
Gene Group (FlyBase)
BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS -
Basic helix-loop-helix (bHLH) transcription factors are sequence-specific DNA-binding proteins that regulate transcription. They are characterized by a 60 amino acid region comprising a basic DNA binding domain followed by a HLH motif formed from two amphipathic α-helices connected by a loop. bHLH transcription factors form homo- and hetero-dimeric complexes, which bind to a E box consensus sequence. (Adapted from PMID:15186484).
HYPOXIA-INDUCIBLE FACTOR -
Hypoxia-inducible factor (HIF) mediates hypoxia-dependent transcription. It is a heterodimeric basic helix-loop-helix transcription factor complex composed of a constitutively expressed HIF-β subunit and an oxygen-regulated HIF-α subunit. (Adapted from FBrf0190953).
Pathway (FlyBase)
INSULIN-LIKE RECEPTOR SIGNALING PATHWAY CORE COMPONENTS -
The Insulin-like Receptor (IR) signaling pathway in Drosophila is initiated by the binding of an insulin-like peptides to the Insulin-like receptor (InR). (Adapted from FBrf0232297, FBrf0230017 and FBrf0229989.)
Protein Function (UniProtKB)
Functions as a transcriptional regulator of the adaptive response to hypoxia. Binds to core DNA sequence 5'-[AG]CGTG-3' within the hypoxia response element (HRE) of target gene promoters.
(UniProt, Q24167)
Summary (Interactive Fly)

bHLH-PAS domain transcription factor - a key regulator of responses to hypoxia - mediates mitochondrial retrograde signaling - regulates lifespan extension by inhibiting c-Myc-TFAM signaling and mitochondrial biogenesis

Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
4

Please see the JBrowse view of Dmel\sima 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 Q24167)

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

Tissue-specific extension of 3' UTRs observed during later stages (FBrf0218523, FBrf0219848); all variants may not be annotated

Gene model reviewed during 5.47

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

Gene model reviewed during 5.53

Gene model includes transcripts encoding non-overlapping portions of the full CDS.

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0344374
6178
1507
FBtr0344375
3543
426
FBtr0344373
4704
869
FBtr0344376
5978
1593
Additional Transcript Data and Comments
Reported size (kB)

6.1 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0310747
165.8
1507
5.01
FBpp0310748
47.6
426
8.53
Polypeptides with Identical Sequences

None of the polypeptides share 100% sequence identity.

Additional Polypeptide Data and Comments
Reported size (kDa)

1505 (aa); 150 (kD observed)

Comments
External Data
Subunit Structure (UniProtKB)

Efficient DNA binding requires dimerization with another bHLH protein. Interacts with Vhl.

(UniProt, Q24167)
Domain

The oxygen-dependent degradation (ODD) domain is required for cytoplasmic localization in normoxia.

(UniProt, Q24167)
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\sima 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).

-2.13

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
organism | ubiquitous

Comment: maternally deposited

Additional Descriptive Data

sima is expressed in most or all cells in the embryo from the blastoderm stage to the end of embryogenesis.

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
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\sima 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
Images
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 33 )
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 sima
Transgenic constructs containing regulatory region of sima
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) (28)
7 of 14
Yes
Yes
7 of 14
Yes
Yes
1  
6 of 14
No
Yes
4 of 14
No
No
4 of 14
No
No
1  
3 of 14
No
No
3 of 14
No
No
2 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  
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
1  
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
2  
1 of 14
No
No
1  
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
3  
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) (19)
7 of 14
Yes
Yes
7 of 14
Yes
Yes
6 of 14
No
Yes
4 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
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
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (20)
8 of 14
Yes
Yes
8 of 14
Yes
Yes
7 of 14
No
Yes
4 of 14
No
No
4 of 14
No
No
3 of 14
No
No
2 of 14
No
No
1 of 14
No
No
2  
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
1 of 14
No
No
1  
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (14)
6 of 13
Yes
Yes
6 of 13
Yes
Yes
3 of 13
No
No
3 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
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Danio rerio (Zebrafish) (30)
8 of 14
Yes
Yes
8 of 14
Yes
Yes
8 of 14
Yes
Yes
8 of 14
Yes
Yes
7 of 14
No
Yes
4 of 14
No
Yes
4 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
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
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)
7 of 14
Yes
Yes
4 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Anopheles gambiae (African malaria mosquito) (15)
8 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:sima. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (12)
7 of 13
6 of 13
3 of 13
1 of 13
1 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 ( 0 )
Allele
Disease
Evidence
References
Potential Models Based on Orthology ( 1 )
Human Ortholog
Disease
Evidence
References
Modifiers Based on Experimental Evidence ( 4 )
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
Interaction Browsers

Please see the Physical Interaction reports below for full details
protein-protein
Physical Interaction
Assay
References
RNA-protein
Physical Interaction
Assay
References
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
Subunit Structure (UniProtKB)
Efficient DNA binding requires dimerization with another bHLH protein. Interacts with Vhl.
(UniProt, Q24167 )
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
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
3-100
Cytogenetic map
Sequence location
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
99D3-99D7
Limits computationally determined from genome sequence between P{PZ}ncd05884 and P{lacW}l(3)s2500s2500
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
99E1-99E2
(determined by in situ hybridisation)
99D6-99D9
(determined by in situ hybridisation)
Experimentally Determined Recombination Data
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (117)
Genomic Clones (42)
cDNA Clones (70)
 

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
    Antibody Information
    Laboratory Generated Antibodies
     

    polyclonal

    Commercially Available Antibodies
     
    Cell Line Information
    Publicly Available Cell Lines
     
      Other Stable Cell Lines
       
        Other Comments

        New annotation (CG31031) in release 3 of the genome annotation.

        Isolated from a genomic library using a fragment containing the sim basic helix-loop-helix region as a probe, under reduced stringency conditions.

        sima has been cloned and sequenced.

        Relationship to Other Genes
        Source for database merge of

        Source for merge of: sima l(3)j11B7

        Source for merge of: sima CG31031

        Additional comments

        Annotations CG7951 and CG31031 merged as CG45051 in release 5.53 of the genome annotation; merge based primarily on RNA-Seq junction and coverage data.

        Nomenclature History
        Source for database identify of
        Nomenclature comments
        Etymology
        Synonyms and Secondary IDs (32)
        Reported As
        Symbol Synonym
        sima
        (Meraner et al., 2026, Ryu et al., 2026, Li et al., 2025, Naik et al., 2025, Richhariya et al., 2025, Sorianello et al., 2025, Wang et al., 2025, Zhao et al., 2025, Campbell et al., 2024, Feng et al., 2024, Turingan et al., 2024, Vesala et al., 2024, Olivares et al., 2023, Havula et al., 2022, Lee et al., 2022, Liu et al., 2022, Ren et al., 2022, Simões et al., 2022, Baker et al., 2021, Bilder et al., 2021, Girard et al., 2021, Joy et al., 2021, Millet-Boureima et al., 2021, Zhang et al., 2021, Barretto et al., 2020, Li et al., 2020, Nakajima et al., 2020, Perez-Gomez et al., 2020, Banerjee et al., 2019, Best, 2019, Chen et al., 2019, Hall et al., 2019, Meltzer et al., 2019, Nicholson et al., 2019, Shokri et al., 2019, Texada et al., 2019, Wong et al., 2019, Ariss et al., 2018, Sakakibara et al., 2018, Fochler et al., 2017, Lin et al., 2017, Misra et al., 2017, Transgenic RNAi Project members, 2017-, De Lella Ezcurra et al., 2016, Perez-Perri et al., 2016, Schwartz et al., 2016, Vinayagam et al., 2016, Bandarra et al., 2015, Cagin et al., 2015, Dong et al., 2015, Gene Disruption Project members, 2015-, Palmer and Deng, 2015, Wang et al., 2015, Zarndt et al., 2015, Ashwal-Fluss et al., 2014, Bandarra et al., 2014, Gersten et al., 2014, Wong et al., 2014, Bonke et al., 2013, Chow et al., 2013, Lőw et al., 2013, Mandilaras et al., 2013, Mortimer and Moberg, 2013, Schertel et al., 2013, Spokony and White, 2013.5.10, Zhou and Haddad, 2013, Chakrabarti et al., 2012, Gurudatta et al., 2012, Kim et al., 2012, Rodriguez et al., 2012, Spokony, 2012.12.12, Ali et al., 2011, Guest et al., 2011, Harrison and Haddad, 2011, Mukherjee et al., 2011, van Uden et al., 2011, Acevedo et al., 2010, Doronkin et al., 2010, Hsouna et al., 2010, Lunardi et al., 2010, Mortimer and Moberg, 2009, Qian and Bodmer, 2009, Vigne et al., 2009, Centanin et al., 2008, Khokhar et al., 2008, Vigne and Frelin, 2008, Arquier et al., 2006, Baird et al., 2006, Centanin et al., 2005, Dekanty et al., 2005, FlyBase, 1992-)
        Secondary FlyBase IDs
        • FBgn0015542
        • FBgn0011432
        • FBgn0051031
        Datasets (0)
        Study focus (0)
        Experimental Role
        Project
        Project Type
        Title
        Study result (0)
        Result
        Result Type
        Title
        External Crossreferences and Linkouts ( 82 )
        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 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
        KEGG Genes - Molecular building blocks of life in the genomic space.
        MARRVEL_MODEL - MARRVEL (model organism gene)
        Linkouts
        Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
        DroID - A comprehensive database of gene and protein interactions.
        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
        FlyMet - A comprehensive tissue-specific metabolomics resource for Drosophila.
        iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
        Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
        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 (257)