ID ACTPP_ACTEQ Reviewed; 20 AA. AC P0C1H1; DT 27-JUN-2006, integrated into UniProtKB/Swiss-Prot. DT 27-JUN-2006, sequence version 1. DT 01-OCT-2014, entry version 28. DE RecName: Full=Equinatoxin-1''; DE AltName: Full=Equinatoxin I''; DE Flags: Fragment; OS Actinia equina (Beadlet anemone). OC Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria; OC Nynantheae; Actiniidae; Actinia. OX NCBI_TaxID=6106; RN [1] RP PROTEIN SEQUENCE. RX PubMed=10414864; DOI=10.1016/S0041-0101(99)00082-3; RA Anderluh G., Krizaj I., Strukelj B., Gubensek F., Macek P., RA Pungercar J.; RT "Equinatoxins, pore-forming proteins from the sea anemone Actinia RT equina, belong to a multigene family."; RL Toxicon 37:1391-1401(1999). RN [2] RP AMINO-ACID COMPOSITION, AND LETHAL DOSE. RX PubMed=2903587; DOI=10.1016/0041-0101(88)90183-3; RA Macek P., Lebez D.; RT "Isolation and characterization of three lethal and hemolytic toxins RT from the sea anemone Actinia equina L."; RL Toxicon 26:441-451(1988). RN [3] RP REVIEW. RX PubMed=19268680; DOI=10.1016/j.toxicon.2009.02.026; RA Kristan K.C., Viero G., Dalla Serra M., Macek P., Anderluh G.; RT "Molecular mechanism of pore formation by actinoporins."; RL Toxicon 54:1125-1134(2009). CC -!- FUNCTION: Pore-forming protein that forms cations-selective CC hydrophilic pores of around 1 nm and causes cardiac stimulation CC and hemolysis. Pore formation is a multi-step process that CC involves specific recognition of membrane sphingomyelin (but CC neither cholesterol nor phosphatidylcholine) using aromatic rich CC region and adjacent phosphocholine (POC) binding site, firm CC binding to the membrane (mainly driven by hydrophobic CC interactions) accompanied by the transfer of the N-terminal region CC to the lipid-water interface and finally pore formation after CC oligomerization of several monomers. Cytolytic effects include red CC blood cells hemolysis, platelet aggregation and lysis, cytotoxic CC and cytostatic effects on fibroblasts. Lethality in mammals has CC been ascribed to severe vasospasm of coronary vessels, cardiac CC arrhythmia, and inotropic effects (By similarity). {ECO:0000250}. CC -!- SUBUNIT: Tetramer in the presence of a lipidic interface. Monomer, CC in soluble state (By similarity). {ECO:0000250}. CC -!- SUBCELLULAR LOCATION: Secreted. Nematocyst. Target cell membrane CC {ECO:0000250}. Note=Forms an alpha-helical membrane channel in the CC prey. {ECO:0000250}. CC -!- DOMAIN: The N-terminal region, before the pore is formed, is bound CC to the lipid membrane. It partitions into the lipid-water CC interface and stabilizes the monomeric molecule on the membrane. CC Finally, it traverses the bilayer, thus forming the transmembrane CC pore (By similarity). {ECO:0000250}. CC -!- TOXIC DOSE: LD(50) is 23 ug/kg by intravenous injection into mice. CC {ECO:0000269|PubMed:2903587}. CC -!- MISCELLANEOUS: The discrimination between sphingomyelin and CC phosphatidylcholine occurs in the region directly below the CC phosphorylcholine headgroup. {ECO:0000250}. CC -!- SIMILARITY: Belongs to the sea anemone actinoporin family. CC {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW. DR GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell. DR GO; GO:0044218; C:other organism cell membrane; IEA:UniProtKB-SubCell. DR GO; GO:0044179; P:hemolysis in other organism; IEA:UniProtKB-KW. DR GO; GO:0006811; P:ion transport; IEA:UniProtKB-KW. PE 1: Evidence at protein level; KW Cytolysis; Direct protein sequencing; Hemolysis; Ion transport; KW Membrane; Nematocyst; Secreted; Target cell membrane; Target membrane; KW Toxin; Transmembrane; Transport. FT PEPTIDE 1 >20 Equinatoxin-1''. FT /FTId=PRO_0000244624. FT REGION 3 12 Plays an important role in the hemolytic FT activity. {ECO:0000250}. FT REGION 11 >20 N-terminal region. {ECO:0000250}. FT NON_TER 20 20 SQ SEQUENCE 20 AA; 1960 MW; FA32B426009FF5FA CRC64; SVAVAGAVIE GATLTFNVLQ //