P0C1H1 · ACTPP_ACTEQ

Function

function

Pore-forming protein that forms cations-selective hydrophilic pores of around 1 nm and causes cardiac stimulation and cytolysis. Pore formation is a multi-step process that involves specific recognition of membrane sphingomyelin (but neither cholesterol nor phosphatidylcholine) using aromatic rich region and adjacent phosphocholine (POC) binding site, firm binding to the membrane (mainly driven by hydrophobic interactions) accompanied by the transfer of the N-terminal region to the lipid-water interface and finally pore formation after oligomerization of monomers. Cytolytic effects include red blood cells hemolysis, platelet aggregation and lysis, cytotoxic and cytostatic effects on fibroblasts. Lethality in mammals has been ascribed to severe vasospasm of coronary vessels, cardiac arrhythmia, and inotropic effects.

GO annotations

all annotationsall molecular functionvirus receptor activitydna bindingrna bindingcytoskeletal motor activitycatalytic activitygtpase activitystructural molecule activitytransporter activitycytoskeletal protein bindinglipid bindingcyclase activityantioxidant activityoxidoreductase activitytransferase activityhydrolase activitylyase activityisomerase activityligase activityprotein tag activitycargo receptor activityhistone bindingprotein folding chaperonetranslation regulator activitynutrient reservoir activityreceptor ligand activitymolecular transducer activitymolecular adaptor activitytoxin activitycell adhesion mediator activitymolecular function regulator activityvirus coreceptor activitycatalytic activity, acting on a proteincatalytic activity, acting on dnacatalytic activity, acting on rnamolecular carrier activitytranscription regulator activitygeneral transcription initiation factor activitymolecular sensor activitymolecular sequestering activityatp-dependent activityother molecular functionall biological processmitotic cell cyclecytokinesiscytoplasmic translationimmune system processmuscle system processcirculatory system processrenal system processrespiratory system processcarbohydrate metabolic processgeneration of precursor metabolites and energydna replicationdna repairdna recombinationchromatin organizationdna-templated transcriptionregulation of dna-templated transcriptiontrna metabolic processprotein foldingprotein glycosylationamino acid metabolic processmodified amino acid metabolic processlipid metabolic processvitamin metabolic processsulfur compound metabolic processintracellular protein transportnucleocytoplasmic transportautophagyinflammatory responsemitochondrion organizationcytoskeleton organizationmicrotubule-based movementperoxisome organizationlysosome organizationchromosome segregationcell adhesionestablishment or maintenance of cell polarityprogrammed cell deathphotosynthesismrna metabolic processsnrna metabolic processvesicle-mediated transportreproductive processdigestive system processsignalingcell differentiationprotein catabolic processextracellular matrix organizationregulatory ncrna-mediated gene silencingtelomere organizationcell junction organizationwound healingribosome biogenesiscilium organizationanatomical structure developmentcell motilitynervous system processendocrine processprotein maturationtransmembrane transportnucleobase-containing small molecule metabolic processhepaticobiliary system processmembrane organizationprotein-containing complex assemblycell wall organization or biogenesisnitrogen cycle metabolic processprotein localization to plasma membranedefense response to other organismdetoxificationmeiotic nuclear divisionmitotic nuclear divisionmitochondrial gene expressioncarbohydrate derivative metabolic processother biological processall cellular componentnuclear chromosomeextracellular regionextracellular spacecell wallnucleusnuclear envelopenucleoplasmchromosomenucleolusmitochondrionlysosomeendosomevacuoleperoxisomeendoplasmic reticulumgolgi apparatuslipid dropletmicrotubule organizing centercytosolribosomecytoskeletonplasma membraneciliumplastidthylakoidexternal encapsulating structureextracellular matrixcytoplasmic vesicleorganelleother cellular component
Cell color indicative of number of GO terms
AspectTerm
Cellular Componentextracellular region
Cellular Componentmembrane
Cellular Componentnematocyst
Cellular Componentother organism cell membrane
Molecular Functiontoxin activity
Biological Processkilling of cells of another organism
Biological Processmonoatomic ion transport

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Equinatoxin-1''
  • Alternative names
    • DELTA-actitoxin
    • Equinatoxin I''

Organism names

Accessions

  • Primary accession
    P0C1H1

Subcellular Location

Secreted
Nematocyst
Target cell membrane
Note: Forms an alpha-helical membrane channel in the prey.

Keywords

Phenotypes & Variants

Toxic dose

LD50 is 23 ug/kg by intravenous injection into mice.

PTM/Processing

Features

Showing features for peptide.

TypeIDPosition(s)Description
PeptidePRO_00002446241-20Equinatoxin-1''

Interaction

Subunit

Octamer or nonamer in membranes. Monomer in the soluble state.

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region3-12Plays an important role in the hemolytic activity
Region11-20N-terminal region

Domain

Composed of a long N-terminal alpha-helix and a core region rich in beta-sheet structures. Before the pore formation, the alpha-helix binds the lipid membrane, partitions into the lipid-water interface and stabilizes the monomeric molecule on the membrane. Finally, it traverses the bilayer, thus forming the transmembrane pore.

Sequence similarities

Keywords

Family and domain databases

Sequence

  • Sequence status
    Fragment
  • Length
    20
  • Mass (Da)
    1,960
  • Last updated
    2006-06-27 v1
  • Checksum
    FA32B426009FF5FA
SVAVAGAVIEGATLTFNVLQ

Features

Showing features for non-terminal residue.

TypeIDPosition(s)Description
Non-terminal residue20

Keywords

Similar Proteins

Disclaimer

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