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General Information
Symbol
Dmel\cact
Species
D. melanogaster
Name
cactus
Annotation Symbol
CG5848
Feature Type
FlyBase ID
FBgn0000250
Gene Model Status
Stock Availability
Gene Snapshot
cactus (cact) encodes the homolog of mammalian IkappaB. cact product acts as an inhibitor of NF-kappaB signaling by binding to the products of dl and Dif, which prevents their nuclear translocation. Toll signaling promotes the destruction of cact protein, which allows the products of dl and Dif to enter the nucleus and regulate gene expression. [Date last reviewed: 2019-03-21]
Also Known As
cac, BG:DS02740.15 , fs(2)ltoRN48
Key Links
Genomic Location
Cytogenetic map
Sequence location
2L:16,313,036..16,326,207 [-]
Recombination map
2-52
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 NF-kappa-B inhibitor family. (Q03017)
Molecular Function (GO)
[Detailed GO annotations]
Experimental Evidence
Predictions / Assertions
-
Summaries
Pathway (FlyBase)
Negative Regulators of Toll-NF-KappaB Signaling Pathway -
In Drosophila, the canonical Toll signaling pathway is initiated by the binding of a spatzle ligand to Toll (Tl) or a Toll-like receptor leading to the nuclear localization of the NF-κB (dl or Dif) transcription factor. Negative regulators of Toll-NF-κB Signaling lead to the increased cytosolic retention of the NF-κB proteins dl or Dif and/or repression of target gene transcription. (Adapted from FBrf0091014 and FBrf0223077).
Gene Group (FlyBase)
NUCLEAR FACTOR - KAPPA B INHIBITOR FAMILY -
The activity of NF-κB transcription factors is regulated by interaction with inhibitory IκB proteins. IκB family members are characterized by multiple ankyrin repeat regions through which they bind Rel homology domain of NF-κB transcription factors. (Adapted from FBrf0233452.)
Protein Function (UniProtKB)
Involved in the formation of the dorsoventral pattern. It inhibits nuclear translocation of the dorsal morphogen in the dorsal region of the embryo. Acts as a negative regulator of the NF-kappa-B (rel) signaling pathway. Cact is degraded by IKKbeta, this is essential for NF-kappa-B (rel) activation.
(UniProt, Q03017)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
cact: cactus (T. Schupbach)
Maternal-effect lethal mutant; embryos from homozygous mothers appear "ventralized"; at differentiation they form only a narrow strip of dorsal cuticle, whereas ventral setal belts are expanded and encircle in irregular fashion most of the embryonic periphery. At gastrulation the germband hardly extends at all, and the posterior midgut invaginates close to the posterior pole. Cephalic furrow is more pronounced than in wildtype.
Summary (Interactive Fly)
Gene Model and Products
Number of Transcripts
5
Number of Unique Polypeptides
2

Please see the GBrowse view of Dmel\cact or the JBrowse view of Dmel\cact 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
Annotated transcripts do not represent all supported alternative splices within 5' UTR.
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.48
Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0080844
1893
500
FBtr0080845
2005
500
FBtr0080846
2356
482
FBtr0080847
2178
500
FBtr0337081
1999
500
Additional Transcript Data and Comments
Reported size (kB)
2.5, 2.1 (northern blot)
2.6, 2.2, 1.7 (northern blot)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0080402
53.8
500
4.47
FBpp0080403
53.8
500
4.47
FBpp0080404
51.6
482
4.45
FBpp0089296
53.8
500
4.47
FBpp0308004
53.8
500
4.47
Polypeptides with Identical Sequences

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

500 aa isoforms: cact-PA, cact-PB, cact-PD, cact-PE
Additional Polypeptide Data and Comments
Reported size (kDa)
500 (aa); 54 (kD)
500, 482 (aa); 53, 52 (kD)
Comments
Disulfide crosslinking studies were used to show that dl and cact proteins exist as three different complexes in the embyro. Complex 1 (190kD) is a dl homodimer (dl2). Complex 2 (270kD) consists of a complex 1 and a cact molecule (dl2cact). Complex 3 is a cact protein complex.
One of a couple of products generated by alternative splicing.
cact protein was shown to inhibit binding of the dl protein to the zen promoter in vitro.
The cact proteins are identical for the first 477 amino acids and differ at their 3'' termini. cact protein inhibits the binding of the dl protein to DNA in vitro. The ankyrin repeats were shown to be necessary for this inhibition. The cact protein ankyrin repeats were shown to bind dl protein directly. In vivo, the majority of cact protein associated with dl is phosphorylated. cact protein has high homology in the repeat region to members of the IκB family including bcl-3, p100, MAD-3, the precursor to KBF1/p50/IκBβ, and pp40.
The cact proteins are identical for the first 477 amino acids and differ at their 3'' termini. cact inhibits the binding of the dl protein to DNA in vitro. The ankyrin repeats were shown to be necessary for this inhibition. The cact protein ankyrin repeats were shown to bind dl protein directly. In vivo, the majority of cact protein associated with dl is phosphorylated. cact has high homology in the repeats region to members of the IκB family including bcl-3, p100, MAD-3, the precursor to KBF1/p50/IκBγ, and pp40.
The cact proteins are identical for the first 477 amino acids and differ at their 3' termini. cact inhibits the binding of the dl protein to DNA in vitro. The ankyrin repeats were shown to be necessary for this inhibition. The cact protein ankyrin repeats were shown to bind dl protein directly. In vivo, the majority of cact protein associated with dl is phosphorylated. cact has high homology in the repeats region to members of the IκB family including bcl-3, p100, MAD-3, the precursor to KBF1/p50/IκBγ, and pp40.
The cact proteins are identical for the first 477 amino acids and differ at their 3' termini. cact protein inhibits the binding of the dl protein to DNA in vitro. The ankyrin repeats were shown to be necessary for this inhibition. The cact protein ankyrin repeats were shown to bind dl protein directly. In vivo, the majority of cact protein associated with dl is phosphorylated. cact protein has high homology in the repeat region to members of the IκB family including bcl-3, p100, MAD-3, the precursor to KBF1/p50/IκBβ, and pp40.
External Data
Subunit Structure (UniProtKB)
Phosphorylated isoform A binds to dorsal (dl); inhibits dl translocation to the nucleus and therefore from binding to DNA. In vitro, interacts with IKKbeta. Interacts with cactin and kappa-B-Ras.
(UniProt, Q03017)
Post Translational Modification
Activated IKKbeta phosphorylates cact.
(UniProt, Q03017)
Crossreferences
InterPro - A database of protein families, domains and functional sites
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\cact 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 (18 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from physical interaction with FLYBASE:Dif; FB:FBgn0011274
inferred from physical interaction with FLYBASE:dl; FB:FBgn0260632
inferred from physical interaction with UniProtKB:Q9VR99
(assigned by UniProt )
inferred from physical interaction with UniProtKB:Q9VEZ5
(assigned by UniProt )
Terms Based on Predictions or Assertions (0 terms)
Biological Process (13 terms)
Terms Based on Experimental Evidence (10 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
traceable author statement
Cellular Component (3 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
inferred from high throughput 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

northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
Expression pattern inferred from unspecified enhancer trap line.
cact transcript is expressed in salivary glands at puparium formation at the end of the last larval ecdysone pulse, and at 12 hours APF at the end of the prepupal ecdyosne pulse.
Levels of the 2.1kb cact transcript decline rapidly after 4 hours of development.
The 2.5kb cact transcript appears at 2 hours and persists at low levels throughout development.
The 2.2kb cact transcript is the most abundant cact transcript and is present throughout development. It is most abundant in unfertilized eggs and early embryos and declines significantly thereafter.
The 2.6kb cact transcript is present from about 4hr onwards.
The 1.7kb cact transcript is produced in unfertilized eggs and 0-4hr embryos.
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
immuno-electron microscopy
Stage
Tissue/Position (including subcellular localization)
Reference
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
Expression of cact is seen in the neuromuscular junction of wildtype fly when observed at 3 days post-eclosion, but is weaker at 60 days post-eclosion.
cact colocalizes with Fas2 at the larval neuromuscular junction.
cact protein is diffusely distributed in the nucleus and cytoplasm of somatic muscles during the last hours of larval development, and though the first four hours of pupariation. cact protein is enriched in the subsynaptic reticulum of type I synaptic boutons. A similar distribution is observed in adult somatic muscles.
The level of cact protein in 0-3hr embyros of three genetic backgrounds was studied. One is dorsalventral signal constitutive (Tl8), one wild type, and one signal deficient (gd2). cact levels are lowest in the signal constitutive mutant, intermediate in wild type, and highest in signal deficient embryos. These differences are apparent as early as stage 2. Furthermore, cact protein is present in a dorsoventral gradient. High levels of protein are present in the dorsal cytoplasm where no intracellular signal transduction occurs and little protein is found in the ventral cytoplasm where signalling is strongest. In Tl8 and gd2 embryos, cact protein levels are uniformly low or high respectively.
Marker for
Subcellular Localization
CV Term
Evidence
References
inferred from high throughput 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\cact 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
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 80 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 35 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of cact
Transgenic constructs containing regulatory region of cact
Deletions and Duplications ( 69 )
Not disrupted in
Partially 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
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (4)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
8 of 15
Yes
Yes
 
4 of 15
No
Yes
3 of 15
No
Yes
 
2 of 15
No
Yes
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (4)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
8 of 15
Yes
Yes
5 of 15
No
Yes
3 of 15
No
Yes
2 of 15
No
Yes
Rattus norvegicus (Norway rat) (3)
8 of 13
Yes
Yes
5 of 13
No
Yes
3 of 13
No
Yes
Xenopus tropicalis (Western clawed frog) (2)
4 of 12
Yes
Yes
3 of 12
No
Yes
Danio rerio (Zebrafish) (5)
8 of 15
Yes
Yes
8 of 15
Yes
Yes
3 of 15
No
Yes
3 of 15
No
Yes
3 of 15
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (3)
2 of 15
Yes
Yes
1 of 15
No
Yes
1 of 15
No
No
Arabidopsis thaliana (thale-cress) (1)
1 of 9
Yes
Yes
Saccharomyces cerevisiae (Brewer's yeast) (0)
No records found.
Schizosaccharomyces pombe (Fission yeast) (0)
No records found.
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG091907K1 )
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 willistoni
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG091509LD )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Mayetiola destructor
Hessian fly
Mayetiola destructor
Hessian fly
Anopheles darlingi
American malaria mosquito
Anopheles gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W0ANP )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Bombyx mori
Silkmoth
Danaus plexippus
Monarch butterfly
Danaus plexippus
Monarch butterfly
Heliconius melpomene
Postman butterfly
Apis florea
Little honeybee
Apis florea
Little honeybee
Apis florea
Little honeybee
Apis mellifera
Western honey bee
Apis mellifera
Western honey bee
Apis mellifera
Western honey bee
Bombus impatiens
Common eastern bumble bee
Bombus terrestris
Buff-tailed bumblebee
Linepithema humile
Argentine ant
Linepithema humile
Argentine ant
Megachile rotundata
Alfalfa leafcutting bee
Nasonia vitripennis
Parasitic wasp
Nasonia vitripennis
Parasitic wasp
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) ( EOG090X0AKJ )
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
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( EOG091G0GOB )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strongylocentrotus purpuratus
Purple sea urchin
Ciona intestinalis
Vase tunicate
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (0)
No records found.
Human Disease Associations
FlyBase Human Disease Model Reports
Disease Model Summary Ribbon
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 1 )
Allele
Disease
Evidence
References
Potential Models Based on Orthology ( 0 )
Human Ortholog
Disease
Evidence
References
Modifiers Based on Experimental Evidence ( 1 )
Allele
Disease
Interaction
References
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
 
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.
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
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
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)
Phosphorylated isoform A binds to dorsal (dl); inhibits dl translocation to the nucleus and therefore from binding to DNA. In vitro, interacts with IKKbeta. Interacts with cactin and kappa-B-Ras.
(UniProt, Q03017 )
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 (genetic) - An integrated Molecular Interaction Database
MIST (protein-protein) - An integrated Molecular Interaction Database
Pathways
Gene Group - Pathway Membership (FlyBase)
Negative Regulators of Toll-NF-KappaB Signaling Pathway -
In Drosophila, the canonical Toll signaling pathway is initiated by the binding of a spatzle ligand to Toll (Tl) or a Toll-like receptor leading to the nuclear localization of the NF-κB (dl or Dif) transcription factor. Negative regulators of Toll-NF-κB Signaling lead to the increased cytosolic retention of the NF-κB proteins dl or Dif and/or repression of target gene transcription. (Adapted from FBrf0091014 and FBrf0223077).
External Data
Genomic Location and Detailed Mapping Data
Chromosome (arm)
2L
Recombination map
2-52
Cytogenetic map
Sequence location
2L:16,313,036..16,326,207 [-]
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
35F1-35F1
Limits computationally determined from genome sequence between P{EP}fzyEP1028&P{lacW}mRpL4k14608 and P{PZ}dacP
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
35F10-35F11
(determined by in situ hybridisation)
35F1-36A1
(determined by in situ hybridisation)
Experimentally Determined Recombination Data
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (27)
Genomic Clones (21)
cDNA Clones (132)
 

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: cact CG5848
Source for database merge of
Additional comments
A dorsalising activity for the heterologous ea, spz and Tl proteins in UV-ventralised X.laevis embryos is demonstrates. The activity is inhibited by co-injection of a dominant cact variant.
Other Comments
S2 cells treated with dsRNA generated against this gene show reduced phagocytosis of Candida albicans compared to untreated cells.
dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
There appear to be two distinct, redundantly acting determinants in the N terminus of cact that direct dl group-dependant degradation.
dpp signalling increases cact protein levels by reducing a signal-independent component of cact protein degradation.
Ventral signal dependent modification of cact and dl may be required for the graded nuclear import of dl.
cact acts in a cell-autonomous manner in the fat body.
A linear activation cascade spz-Tl-cact-dl/Dif leads to the induction of the Drs gene in larval fat body cells.
cact is up-regulated in response to immune challenge.
The Tl/cact signal transduction pathway has a role in regulating hemocyte proliferation and hemocyte density in the larva.
Tl pathway is required for the nuclear import of dl in the immune response, but not required for the nuclear import of Dif. Cytoplasmic retention of both dl and Dif depends on cact protein. The two signalling pathways that target cact for degradation must discriminate between cact-dl and cact-Dif complexes.
The molecular evolution of the Rel/NF-κB and IκB proteins is studied in parallel. Phylogenetic analysis allows the structure of the putative ancestor genes to be defined and proposes and evolutionary model that clusters both families in a unique Rel/NF-κB/IκB superfamily.
Casein kinase II specifically phosphorylates a set of serine residues within the cact PEST domain. These serines are phosphorylated in vivo and are required for wild-type cact protein activity.
Casein kinase II phosphorylates Ser468 (a residue in the PEST domain) of cact in vitro.
Genetic experiments propose that tub, pll, cact and dl form a complex, the formation of which is essential for signal transduction.
cact forms a concentration gradient inversely correlated to the nuclear translocation gradient of dl. Deletions of the N-terminus and C-terminus of cact reveal that two modes of degradation control cact activity: signal-induced degradation and signal-independent degradation, respectively. Genetic evidence indicates degradation of cact is required, but not sufficient, to translocate dl completely into the nucleus.
The embryonic regulatory pathway, comprising the gene products between spz and cact (Tl, tub and pll) but not the genes acting upstream or downstream (ea and dl), is involved in the induction of the Drs gene in adults. Mutations that affect the synthesis of antimicrobial peptides dramatically lower the resistance of flies to infection.
In cultured cells and embryos cact degradation is dependent on a pll mediated signal, mutation of a putative phosphorylation motif blocks signal responsiveness. In embryos there is a gradient of cact protein. In ventral regions cact is degraded allowing dl to translocate into the nuclei, in dorsal regions cact persists, retaining dl in the cytoplasm.
cact protein can be rapidly degraded in response to signalling, degradation requires the action of the dorsal group genes Tl, tub and pll which act just upstream of cact. cact mutants that produce more stable protein than wild type are able to block signalling.
cact inhibits nuclear translocation of dl on the ventral side of the embryo by binding to and retaining dl in the cytoplasm. cact is rapidly degraded in response to signalling from the dorsal ventral pathway between spz and dl/cact, this signal-dependent degradation does not require the presence of dl but does require sequences in the amino terminus or ankyrin repeats of the cact protein. Disruption of the dl-cact complex is a secondary result of cact degradation. Signal independent degradation of free cact requires the carboxy terminal region of the protein that includes a PEST sequence.
cact is subject both to a signal-dependent and signal-independent regulation which require separate regions of the cact molecule.
Increases in intra-cellular Ca2+ levels result in rapid destruction of cact protein and dephosphorylation of dl protein in a Drosophila cell line.
dl protein enhances the biosynthesis and stability of cact.
cact activity blocks the DNA binding and nuclear localisation functions of dl. dl transcriptional activating region is functional in the dl cact complex.
dl is not involved in the formation of melanotic tumours of cact mutations.
Signal-dependent dl phosphorylation is modulated by three intracellular proteins, pll, tub and cact.
Disulfide cross-linking in crude extracts has identified two complexes of cact protein: a cact protein complex and a complex of the cact protein with dl protein.
cact gene product sequesters the dl gene product in the cytoplasm and acts as a promoter-independent inhibitor.
Comparisons of early development to that in other insects have revealed conservation of some aspects of development, as well as differences that may explain variations in early patterning events.
P-elements transposing from a donor site at the cact gene were found to show nearly a three fold preference for transposition to a region of the homologous chromosome containing the cact locus and extending over two or three number divisions. This preferential transposition is likely to result from a physical proximity of homologous chromosomal regions in the nuclei of germline cells.
Studies of protein binding and their conformation suggests that the ankyrin repeats of cact fold together in helical bundles interconnected by diverged loops.
dl and cact are phosphoproteins that form a stable cytoplasmic complex. The cact protein is stabilised by its interaction with dl protein, and the dl-cact complex dissociates when dl protein is targeted to the nucleus.
The cactus gene was cloned starting with a P{lacZ} insertion. Bacterially expressed cactus protein (which has sequence similarity to IκB) inhibits binding to DNA of dorsal protein in vitro. Antisense cactus RNA can phenocopy cactus mutations. Sense cactus RNA rescues its maternal effect mutant phenotype.
The cact protein binds dl in the rel-homology domain of dl.
cact mutations have a ventralizing maternal effect that yield significantly increased axial ratios in pupae.
Mutations in maternal ventral class gene cact interact with RpII140wimp.
cact is a germline-dependent maternal-effect gene. Double mutant analysis of cactus and dorsal group genes demonstrate that cact and dl act downstream of all other dorsal group genes.
Mutations at the fs(2)ltoRN48 locus causes defects in midoogenesis.
Involved in the regulatory hierarchy responsible for the asymmetric distribution and function of zygotic regulatory gene products along the DV axis of early embryos. Weak cact mutants have a similar cuticle phenotype to that of zen- embryos.
Mutations in cact result in a maternal effect phenotype with defects during the early stages of gastrulation and defects in the dorsoventral axis; embryos derived from homozygous females are ventralised.
Origin and Etymology
Discoverer
Etymology
Identification
External Crossreferences and Linkouts ( 120 )
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/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.
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
InterPro - A database of protein families, domains and functional sites
KEGG Genes - Molecular building blocks of life in the genomic space.
KEGG Pathways - Wiring diagrams of molecular interactions, reactions and relations.
modMine - A data warehouse for the modENCODE project
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
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
FlyMine - An integrated database for Drosophila genomics
Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
KEGG Pathways - Wiring diagrams of molecular interactions, reactions and relations.
MIST (genetic) - An integrated Molecular Interaction Database
MIST (protein-protein) - An integrated Molecular Interaction Database
Synonyms and Secondary IDs (17)
Reported As
Symbol Synonym
cact
(Palmer et al., 2019, Al-Ramahi et al., 2018, Behrman et al., 2018, Green et al., 2018, Lee et al., 2018, Christesen et al., 2017, Duneau et al., 2017, Fanti et al., 2017, Park et al., 2017, Wang et al., 2017, Gao et al., 2016, Liu et al., 2016, Sarov et al., 2016, Aradska et al., 2015, Buffolo et al., 2015, Fear et al., 2015, Gene Disruption Project members, 2015-, O'Connell and Reeves, 2015, Xia et al., 2015, Zang et al., 2015, Zhang et al., 2015, Ashwal-Fluss et al., 2014, Bonnay et al., 2014, Kim and Choe, 2014, Fontenele et al., 2013, McIlroy et al., 2013, Samaraweera et al., 2013, Schertel et al., 2013, Vaque et al., 2013, Vaqué et al., 2013, Fukui et al., 2012, Hazelett et al., 2012, Japanese National Institute of Genetics, 2012.5.21, Lemaitre et al., 2012, Yáñez-Cuna et al., 2012, Friedman et al., 2011, Friedman et al., 2011, Toku et al., 2011, Hill-Burns and Clark, 2010, Huang et al., 2010, Kong et al., 2010, Salzer et al., 2010, Ahmad et al., 2009, Fontenele et al., 2009, Luce-Fedrow et al., 2009, Markovic et al., 2009, Obbard et al., 2009, Tan et al., 2008, Heckscher et al., 2007, Koizumi et al., 2007, Levine et al., 2007, Minidorff et al., 2007, Quinones-Coello, 2007, Sandmann et al., 2007, Wu et al., 2007, Zeitouni et al., 2007, Friedman and Perrimon, 2006, Minakhina and Steward, 2006, Ryu et al., 2006, Scuderi et al., 2006, Stroschein-Stevenson et al., 2006, Rehwinkel et al., 2005, Thoetkiattikul et al., 2005, Bruckner et al., 2004, Lazzaro et al., 2004, Lau et al., 2003, Gim et al., 2001, Pickeral et al., 2000, Rutschmann et al., 2000, Schupbach and Wieschaus, 1989)
Name Synonyms
NF-kappa-B inhibitor cactus
female-sterile-(2)-ltoRN48
Secondary FlyBase IDs
  • FBgn0013453
Datasets (0)
Study focus (0)
Experimental Role
Project
Project Type
Title
References (506)