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General Information
Symbol
Dmel\α-Spec
Species
D. melanogaster
Name
α Spectrin
Annotation Symbol
CG1977
Feature Type
FlyBase ID
FBgn0250789
Gene Model Status
Stock Availability
Gene Snapshot
α Spectrin (α-Spec) encodes an essential protein that interacts with the products of β-Spec or kst to form a heterotetramer. It is typically associated with the plasma membrane. It functions in a lipoprotein pathway that delivers dietary fat to the larval fat body for storage. It is also believed to function in asymmetric division of germ line stem cells via cytoplasmic structures called spectrosomes and fusomes. [Date last reviewed: 2019-03-21]
Also Known As
Spectrin, alpha-spectrin, αSpec, l(3)dre3, alpha Spectrin
Key Links
Genomic Location
Cytogenetic map
Sequence location
3L:1,778,485..1,795,328 [-]
Recombination map
3-1.0
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Protein Family (UniProt)
Belongs to the spectrin family. (P13395)
Molecular Function (GO)
[Detailed GO annotations]
Experimental Evidence
Predictions / Assertions
Summaries
Protein Function (UniProtKB)
Spectrin is the major constituent of the cytoskeletal network underlying the erythrocyte plasma membrane. It associates with band 4.1 and actin to form the cytoskeletal superstructure of the erythrocyte plasma membrane. Essential for larval survival and development. Stabilizes cell to cell interactions that are critical for the maintenance of cell shape and subcellular organization within embryonic tissues. Lva and spectrin may form a Golgi-based scaffold that mediates interaction of Golgi bodies with microtubules and facilitates Golgi-derived membrane secretion required for the formation of furrows during cellularization.
(UniProt, P13395)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
l(3)62Bd
Hemizygotes die in first larval instar, with one of seven alleles tested occasionally surviving until the second instar.
αSpec: alpha Spectrin
Structural gene for alpha spectrin, a 234 kd polypeptide that forms an elongated heterodimer with beta spectrin to form an important cytoskeletal component. Product crossreacts with antibodies against mammalian spectrins; can be shown to bind to beta spectrin subunits.
Summary (Interactive Fly)
cytoskeletal protein - structural and docking protein - acts together with integrins to regulate actomyosin and columnarization, and to maintain a mono-layered follicular epithelium
Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
4

Please see the GBrowse view of Dmel\α-Spec or the JBrowse view of Dmel\α-Spec 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
Comments on Gene Model
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.46
Shares 5' UTR with upstream gene.
Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0072789
8221
2415
FBtr0332878
7721
2457
FBtr0332879
8317
2447
FBtr0332880
8251
2425
Additional Transcript Data and Comments
Reported size (kB)
7.292 (compiled cDNA)
8.0 (compiled cDNA)
9.0 (unknown)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0072672
278.3
2415
4.84
FBpp0305100
282.6
2457
4.84
FBpp0305101
281.3
2447
4.83
FBpp0305102
279.5
2425
4.85
Polypeptides with Identical Sequences

None of the polypeptides share 100% sequence identity.

Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
The regions of the tail ends of the α-Spec and β-Spec@ chains that are necessary for interchain binding were mapped in vitro. Segments 20 and 21 and part of 22 of the α chain and segments 2 and 3 and part of 1 of the β chain are required for interchain binding.
External Data
Subunit Structure (UniProtKB)
Native spectrin molecule is a tetramer composed of two antiparallel heterodimers joined head to head so that each end of the native molecule includes the C-terminus of the alpha subunit and the N-terminus of the beta subunit. Interacts with calmodulin in a calcium-dependent manner, interacts with F-actin and also interacts with Lva. Interacts with Ten-m.
(UniProt, P13395)
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\α-Spec using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Gene Ontology (25 terms)
Molecular Function (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 (2 terms)
CV Term
Evidence
References
inferred from sequence or structural similarity
inferred from electronic annotation with InterPro:IPR002048
(assigned by InterPro )
Biological Process (15 terms)
Terms Based on Experimental Evidence (10 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (5 terms)
CV Term
Evidence
References
Cellular Component (7 terms)
Terms Based on Experimental Evidence (7 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
Terms Based on Predictions or Assertions (0 terms)
Expression Data
Expression Summary Ribbons
Colored tiles in ribbon indicate that expression data has been curated by FlyBase for that anatomical location. Colorless tiles indicate that there is no curated data for that location.
For complete stage-specific expression data, view the modENCODE Development RNA-Seq section under High-Throughput Expression below.
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
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
α-Spec protein is localized to all membrane surfaces of cells of the larval salivary gland.
Both tmod and α-Spec immunoreactivity associate with the fusome, but not in the exact same pattern as the germline cyst ages.
Marker for
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\α-Spec in GBrowse 2
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
FLIGHT - Cell culture data for RNAi and other high-throughput technologies
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 38 )
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 α-Spec
Transgenic constructs containing regulatory region of α-Spec
Deletions and Duplications ( 152 )
Disrupted in
Not disrupted in
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
brush border & larval midgut & embryo
microtubule cytoskeleton & axon, with Scer\GAL4elav-C155
microtubule cytoskeleton & nerve terminal, with Scer\GAL4elav-C155
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (12)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
15 of 15
Yes
Yes
6 of 15
No
Yes
2 of 15
No
No
2 of 15
No
No
 
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (12)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
13 of 15
Yes
Yes
6 of 15
No
Yes
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Rattus norvegicus (Norway rat) (7)
12 of 13
Yes
Yes
5 of 13
No
Yes
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
Xenopus tropicalis (Western clawed frog) (9)
6 of 12
Yes
Yes
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
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
Danio rerio (Zebrafish) (13)
13 of 15
Yes
Yes
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Caenorhabditis elegans (Nematode, roundworm) (5)
15 of 15
Yes
Yes
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Arabidopsis thaliana (thale-cress) (0)
No records found.
Saccharomyces cerevisiae (Brewer's yeast) (0)
No records found.
Schizosaccharomyces pombe (Fission yeast) (1)
2 of 12
Yes
No
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG0919004M )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila melanogaster
fruit fly
Drosophila suzukii
Spotted wing Drosophila
Drosophila simulans
Drosophila sechellia
Drosophila erecta
Drosophila yakuba
Drosophila ananassae
Drosophila pseudoobscura pseudoobscura
Drosophila persimilis
Drosophila persimilis
Drosophila willistoni
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG0915002W )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Mayetiola destructor
Hessian fly
Aedes aegypti
Yellow fever mosquito
Anopheles darlingi
American malaria mosquito
Anopheles gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W004F )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Bombyx mori
Silkmoth
Danaus plexippus
Monarch butterfly
Heliconius melpomene
Postman butterfly
Apis florea
Little honeybee
Apis mellifera
Western honey bee
Bombus impatiens
Common eastern bumble bee
Bombus terrestris
Buff-tailed bumblebee
Linepithema humile
Argentine ant
Linepithema humile
Argentine ant
Linepithema humile
Argentine ant
Megachile rotundata
Alfalfa leafcutting bee
Nasonia vitripennis
Parasitic wasp
Dendroctonus ponderosae
Mountain pine beetle
Tribolium castaneum
Red flour beetle
Pediculus humanus
Human body louse
Rhodnius prolixus
Kissing bug
Cimex lectularius
Bed bug
Acyrthosiphon pisum
Pea aphid
Zootermopsis nevadensis
Nevada dampwood termite
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X0041 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strigamia maritima
European centipede
Ixodes scapularis
Black-legged tick
Stegodyphus mimosarum
African social velvet spider
Tetranychus urticae
Two-spotted spider mite
Tetranychus urticae
Two-spotted spider mite
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( EOG091G006T )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (5)
4 of 10
3 of 10
3 of 10
1 of 10
1 of 10
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Model Summary Ribbon
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 3 )
    Modifiers Based on Experimental Evidence ( 1 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v7.1 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
    esyN Network Diagram
    Show neighbor-neighbor interactions:
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Interactions Browser

    Please see the Physical Interaction reports below for full details
    RNA-protein
    Physical Interaction
    Assay
    References
    protein-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    esyN Network Diagram
    esyN Network Key:
    Suppression
    Enhancement

    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)
    Native spectrin molecule is a tetramer composed of two antiparallel heterodimers joined head to head so that each end of the native molecule includes the C-terminus of the alpha subunit and the N-terminus of the beta subunit. Interacts with calmodulin in a calcium-dependent manner, interacts with F-actin and also interacts with Lva. Interacts with Ten-m.
    (UniProt, P13395 )
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    External Data
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3L
    Recombination map
    3-1.0
    Cytogenetic map
    Sequence location
    3L:1,778,485..1,795,328 [-]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    62B4-62B4
    Limits computationally determined from genome sequence between P{EP}rhoEP3704&P{PZ}l(3)0622606226 and P{PZ}dlt04276
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    62B1-62B7
    62B4-62B5
    (determined by in situ hybridisation)
    62B1-62B7
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (16)
    Genomic Clones (18)
     

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

    cDNA Clones (96)
     

    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 GBrowse for alignment of the cDNAs and ESTs to the gene model.

    cDNA clones, fully sequences
    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
      GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
      Antibody Information
      Laboratory Generated Antibodies
      Commercially Available Antibodies
       
      Developmental Studies Hybridoma Bank - Monoclonal antibodies for use in research
      Other Information
      Relationship to Other Genes
      Source for database identify of
      Source for identity of: α-Spec CG1977
      Source for database merge of
      Source for merge of: α-Spec anon- EST:fe2E2
      Source for merge of: klo α-Spec
      Additional comments
      One or more of the processed transcripts for this gene share(s) untranslated sequences with a transcript of an adjacent gene, but encode(s) a single open reading frame (ORF). The non-overlapping ORFs that share untranslated sequences are represented by dlt and α-Spec.
      Other Comments
      α-Spec functions, with β-Spec, at the presynapse as an essential presynaptic scaffold that may link synaptic cell adhesion with the stabilization of the underlying microtubule cytoskeleton.
      dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
      The dlt open reading frame is located within the first intron of α-Spec and the two genes share a common first untranslated exon. Overall orientation not stated: Patj- CG12020- Cdc37- α-Spec+ dlt+ α-Spec+
      Spectrin is necessary for the capture and tethering of membrane associated proteins required for presynaptic neurotransmitter release.
      The absence of spectrins disrupts neurotransmission but does not alter postsynaptic glutamate receptor field function or the ultrastructural localization of presynaptic vesicles. The subcellular location of many synaptic proteins is affected.
      Four EMS induced alleles were identified in a screen for mutations affecting commissure formation in the CNS of the embryo.
      α-Spec is required for ovarian follicle monolayer integrity. Elimination of α-Spec from follicle cells does not appear to prevent the assembly of conventional β-Spec and Ank products at the lateral domain of the follicle cell plasma membrane. However α-Spec is required for the correct localization of ΒH-spectrin to the apical surface.
      The α-Spec gene product is a component of both fusomes and spectrosomes.
      Clonal analysis demonstrates α-Spec is required in the germline (but not in the follicle cells) for cyst formation and oocyte differentiation. Its role in each process is distinct from that of hts protein. The organisation of membrane skeletal proteins is more dependent on α-Spec in the fusome than at the plasma membrane in other cells. The fusome and associated membrane skeleton play a central role in regulating the divisions and differentiation of cyst cells.
      The results of clonal analysis suggest that spectrin is involved in the spatial arrangement of the follicle cell population during oocyte development.
      The hts and α-Spec products are components of the fusome, which is required for ovarian cyst formation.
      Recombinant proteins constructs of α-Spec and β-Spec, whose primary structures correspond to the regions required for tail end interchain binding (segments 19-22 of α-Spec and segments 1-4 of β-Spec), demonstrate that interchain binding depends on multiple sites within both the nonrepetitive segments and adjacent repetitive segments of both chains.
      The structure of one of the repetitive segments of α-Spec has been determined at 1.8 angstrom resolution. The segment consists of a three helix bundle. Hydrophobic interactions between two tandem segments may constrain intersegment flexibility.
      Various regions of the α-Spec molecule exhibit structural autonomy thus enabling fragments of the molecule to fold properly when expressed in bacteria. Results localise the calmodulin binding and calcium binding sites within specific segments of the protein.
      Single repetitive motifs and pairs of motifs can fold into stable conformations similar to that of native α-Spec when their N-terminal ends are 26 residues downstream of the residue that has usually been designated to be the first position of each repetitive motif.
      Mutant hemizygotes are larval lethal; dying in the first or (rarely) second instar.
      Origin and Etymology
      Discoverer
      Etymology
      "klotzchen" means "small building block" in German.
      Identification
      External Crossreferences and Linkouts ( 74 )
      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/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
      BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
      Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
      Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
      Flygut - An atlas of the Drosophila adult midgut
      FlyMine - An integrated database for Drosophila genomics
      GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
      iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
      KEGG Genes - Molecular building blocks of life in the genomic space.
      modMine - A data warehouse for the modENCODE project
      PDB - An information portal to biological macromolecular structures
      SignaLink - A signaling pathway resource with multi-layered regulatory networks.
      Linkouts
      BioGRID - A database of protein and genetic interactions.
      DroID - A comprehensive database of gene and protein interactions.
      DRSC - Results frm RNAi screens
      Developmental Studies Hybridoma Bank - Monoclonal antibodies for use in research
      FLIGHT - Cell culture data for RNAi and other high-throughput technologies
      FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
      Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
      InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
      MIST (protein-protein) - An integrated Molecular Interaction Database
      Synonyms and Secondary IDs (46)
      Reported As
      Symbol Synonym
      FBtr0072789
      alpha Spectrin
      alpha spectrin
      anon-EST:fe2E2
      Name Synonyms
      Alpha Spectrin
      Alpha-spectrin
      alpha-spectrin II
      anon-fast-evolving-2E2
      α Spectrin
      Secondary FlyBase IDs
      • FBgn0026231
      • FBgn0064128
      • FBgn0025219
      • FBgn0002180
      • FBgn0003470
      Datasets (0)
      Study focus (0)
      Experimental Role
      Project
      Project Type
      Title
      References (472)