ID   ACTP_ENTQU              Reviewed;          40 AA.
AC   P0DMX3;
DT   22-JUL-2015, integrated into UniProtKB/Swiss-Prot.
DT   22-JUL-2015, sequence version 1.
DT   25-MAY-2022, entry version 17.
DE   RecName: Full=Cytolysin EnT {ECO:0000303|PubMed:10665806};
DE   AltName: Full=DELTA-actitoxin {ECO:0000305};
DE   Flags: Fragment;
OS   Entacmaea quadricolor (Bubble-tip anemone) (Parasicyonis actinostoloides).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Actiniidae; Entacmaea.
OX   NCBI_TaxID=6118;
RN   [1]
RP   PROTEIN SEQUENCE, AND FUNCTION.
RX   PubMed=10665806; DOI=10.1016/s0041-0101(99)00154-3;
RA   Samejima Y., Yanagisawa M., Aoki-Tomomatsu Y., Iwasaki E., Ando J.,
RA   Mebs D.;
RT   "Amino acid sequence studies on cytolytic toxins from sea anemone
RT   Heteractis magnifica, Entacmaea quadricolor and Stichodactyla mertensii
RT   (Anthozoa).";
RL   Toxicon 38:259-264(2000).
RN   [2]
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 hydrophilic
CC       pores of around 1 nm and causes cytolysis and hemolysis. Pore formation
CC       is a multi-step process that involves specific recognition of membrane
CC       sphingomyelin (but neither cholesterol nor phosphatidylcholine) using
CC       aromatic rich region and adjacent phosphocholine (POC) binding site,
CC       firm binding to the membrane (mainly driven by hydrophobic
CC       interactions) accompanied by the transfer of the N-terminal region to
CC       the lipid-water interface and finally pore formation after
CC       oligomerization of monomers (By similarity). This toxin shows hemolytic
CC       activities (PubMed:10665806). {ECO:0000250|UniProtKB:P39088,
CC       ECO:0000269|PubMed:10665806}.
CC   -!- SUBUNIT: Tetramer in the presence of a lipidic interface. Monomer, in
CC       soluble state. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:P39088}.
CC       Nematocyst {ECO:0000250|UniProtKB:P39088}. Target cell membrane
CC       {ECO:0000250|UniProtKB:P39088}. Note=Forms an alpha-helical membrane
CC       channel in the prey. {ECO:0000250|UniProtKB:P39088}.
CC   -!- DOMAIN: The N-terminal region, before the pore is formed, is bound to
CC       the lipid membrane. It partitions into the lipid-water interface and
CC       stabilizes the monomeric molecule on the membrane. Finally, it
CC       traverses the bilayer, thus forming the transmembrane pore.
CC       {ECO:0000250|UniProtKB:P61914}.
CC   -!- DOMAIN: The Trp-rich region is important for the binding to lipid
CC       membrane. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the actinoporin family. Sea anemone subfamily.
CC       {ECO:0000305}.
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DR   AlphaFoldDB; P0DMX3; -.
DR   SMR; P0DMX3; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell.
DR   GO; GO:0046930; C:pore complex; IEA:InterPro.
DR   GO; GO:0015267; F:channel activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0006812; P:cation transport; IEA:InterPro.
DR   GO; GO:0044179; P:hemolysis in another organism; IEA:UniProtKB-KW.
DR   GO; GO:0046931; P:pore complex assembly; IEA:InterPro.
DR   Gene3D; 2.60.270.20; -; 1.
DR   InterPro; IPR009104; Anemon_actinoporin-like.
DR   InterPro; IPR015926; Cytolysin/lectin.
DR   Pfam; PF06369; Anemone_cytotox; 1.
DR   SUPFAM; SSF63724; SSF63724; 1.
PE   1: Evidence at protein level;
KW   Cytolysis; Direct protein sequencing; Hemolysis; Ion transport; Membrane;
KW   Nematocyst; Secreted; Target cell membrane; Target membrane; Toxin;
KW   Transmembrane; Transport.
FT   CHAIN           1..>40
FT                   /note="Cytolysin EnT"
FT                   /id="PRO_0000433582"
FT   REGION          3..12
FT                   /note="Plays an important role in the hemolytic activity"
FT                   /evidence="ECO:0000250|UniProtKB:P07845"
FT   REGION          11..30
FT                   /note="N-terminal region"
FT                   /evidence="ECO:0000250|UniProtKB:P61914"
FT   NON_TER         40
SQ   SEQUENCE   40 AA;  4096 MW;  9C2BB6084398018D CRC64;
     SLALAGTIIE GASLTFSVLT TILDALGSVS RKIDVGVYNE