ID   CTXI5_MESEU             Reviewed;          35 AA.
AC   P60270;
DT   16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT   16-JAN-2004, sequence version 1.
DT   03-AUG-2022, entry version 52.
DE   RecName: Full=Insectotoxin-I5 {ECO:0000303|PubMed:9891977};
DE   AltName: Full=BeI5;
OS   Mesobuthus eupeus (Lesser Asian scorpion) (Buthus eupeus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34648;
RN   [1]
RP   PROTEIN SEQUENCE, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=9891977; DOI=10.1016/s0014-5793(98)01589-0;
RA   Tytgat J., Debont T., Rostoll K., Mueller G.J., Verdonck F., Daenens P.,
RA   van der Walt J.J., Possani L.D.;
RT   "Purification and partial characterization of a 'short' insectotoxin-like
RT   peptide from the venom of the scorpion Parabuthus schlechteri.";
RL   FEBS Lett. 441:387-391(1998).
CC   -!- FUNCTION: Toxin with unknown function in healthy organisms. On glioma
CC       cells, interacts with chloride channels (probably ClC-3/CLCN3) and MMP2
CC       at the surface of glioma cells. This complex is then internalized via
CC       caveolae, thus inhibiting the chloride channels necessary for cell
CC       shrinkage and tumor propagation. {ECO:0000250|UniProtKB:Q9UAD0}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:9891977}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:9891977}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000250|UniProtKB:P15222}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Chloride
CC       channel inhibitor family. {ECO:0000255|PROSITE-ProRule:PRU00545}.
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DR   PIR; JN0361; JN0361.
DR   AlphaFoldDB; P60270; -.
DR   SMR; P60270; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0017081; F:chloride channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   InterPro; IPR007958; Scorpion_toxinS_Cl_inh.
DR   Pfam; PF05294; Toxin_5; 1.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS51200; SHORT_SCORPION_CHLORIDE; 1.
PE   1: Evidence at protein level;
KW   Chloride channel impairing toxin; Direct protein sequencing;
KW   Disulfide bond; Ion channel impairing toxin; Knottin; Secreted; Toxin;
KW   Voltage-gated chloride channel impairing toxin.
FT   PEPTIDE         1..35
FT                   /note="Insectotoxin-I5"
FT                   /evidence="ECO:0000269|PubMed:9891977"
FT                   /id="PRO_0000044938"
FT   DISULFID        2..19
FT                   /evidence="ECO:0000250|UniProtKB:P15222,
FT                   ECO:0000255|PROSITE-ProRule:PRU00545"
FT   DISULFID        5..26
FT                   /evidence="ECO:0000250|UniProtKB:P15222,
FT                   ECO:0000255|PROSITE-ProRule:PRU00545"
FT   DISULFID        16..31
FT                   /evidence="ECO:0000250|UniProtKB:P15222,
FT                   ECO:0000255|PROSITE-ProRule:PRU00545"
FT   DISULFID        20..33
FT                   /evidence="ECO:0000250|UniProtKB:P15222,
FT                   ECO:0000255|PROSITE-ProRule:PRU00545"
SQ   SEQUENCE   35 AA;  3835 MW;  47D2698E3C0F873F CRC64;
     MCMPCFTTDP NMANKCRDCC GGGKKCFGPQ CLCNR