ID   CAVEJ_VAEME             Reviewed;          33 AA.
AC   P0DPT1;
DT   13-FEB-2019, integrated into UniProtKB/Swiss-Prot.
DT   13-FEB-2019, sequence version 1.
DT   25-MAY-2022, entry version 7.
DE   RecName: Full=Vejocalcin {ECO:0000303|PubMed:27114612};
DE            Short=VjCa {ECO:0000303|PubMed:27114612};
OS   Vaejovis mexicanus (Mexican scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Iurida; Chactoidea; Vaejovidae; Vaejovis.
OX   NCBI_TaxID=993612;
RN   [1]
RP   PROTEIN SEQUENCE, MASS SPECTROMETRY, FUNCTION, SUBCELLULAR LOCATION, AND
RP   3D-STRUCTURE MODELING.
RC   TISSUE=Venom;
RX   PubMed=27114612; DOI=10.1085/jgp.201511499;
RA   Xiao L., Gurrola G.B., Zhang J., Valdivia C.R., SanMartin M., Zamudio F.Z.,
RA   Zhang L., Possani L.D., Valdivia H.H.;
RT   "Structure-function relationships of peptides forming the calcin family of
RT   ryanodine receptor ligands.";
RL   J. Gen. Physiol. 147:375-394(2016).
CC   -!- FUNCTION: This toxin stabilizes ryanodine receptor 1 (RyR1) opening in
CC       a long-lasting subconductance state (60% of the full conductance state)
CC       (PubMed:27114612). Furthermore, it triggers calcium release from
CC       sarcoplasmic vesicles (31 nM are enough to induce a sharp release, and
CC       65% of the total calcium is released after toxin (100 nM) addition)
CC       probably by acting as a cell-penetrating peptide (CPP)
CC       (PubMed:27114612). In addition, it has been shown to dose-dependently
CC       stimulate ryanodine binding to RyR1 (EC(50)=3.7 nM) (PubMed:27114612).
CC       It also augments the bell-shaped calcium-[3H]ryanodine binding curve
CC       that is maximal at about 10 uM calcium concentration (PubMed:27114612).
CC       It binds a different site as ryanodine (By similarity). It acts
CC       synergistically with caffeine (By similarity). In vivo,
CC       intracerebroventricular injection into mice induces neurotoxic
CC       symptoms, followed by death (By similarity).
CC       {ECO:0000250|UniProtKB:A0A1L4BJ42, ECO:0000250|UniProtKB:B8QG00,
CC       ECO:0000250|UniProtKB:P59868, ECO:0000250|UniProtKB:P60254,
CC       ECO:0000269|PubMed:27114612}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:27114612}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:27114612}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000250|UniProtKB:P59868}.
CC   -!- MASS SPECTROMETRY: Mass=3774.92; Method=Unknown;
CC       Evidence={ECO:0000269|PubMed:27114612};
CC   -!- SIMILARITY: Belongs to the scorpion calcin family. {ECO:0000305}.
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DR   AlphaFoldDB; P0DPT1; -.
DR   SMR; P0DPT1; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0019855; F:calcium channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR012632; Scorpion_calcine.
DR   Pfam; PF08099; Toxin_27; 1.
DR   PROSITE; PS60028; SCORPION_CALCINE; 1.
PE   1: Evidence at protein level;
KW   Calcium channel impairing toxin; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Knottin; Neurotoxin;
KW   Ryanodine-sensitive calcium-release channel impairing toxin; Secreted;
KW   Toxin.
FT   CHAIN           1..33
FT                   /note="Vejocalcin"
FT                   /evidence="ECO:0000269|PubMed:27114612"
FT                   /id="PRO_0000446291"
FT   REGION          23..24
FT                   /note="Essential for stimulation of [3H]ryanodine binding
FT                   to RYR1"
FT                   /evidence="ECO:0000250|UniProtKB:P59868,
FT                   ECO:0000250|UniProtKB:P60254"
FT   SITE            31
FT                   /note="Essential for stimulation of [3H]ryanodine binding
FT                   to RYR1"
FT                   /evidence="ECO:0000250|UniProtKB:P59868"
FT   SITE            33
FT                   /note="Essential for stimulation of [3H]ryanodine binding
FT                   to RYR1"
FT                   /evidence="ECO:0000250|UniProtKB:P59868"
FT   DISULFID        3..17
FT                   /evidence="ECO:0000250|UniProtKB:P59868"
FT   DISULFID        10..21
FT                   /evidence="ECO:0000250|UniProtKB:P59868"
FT   DISULFID        16..32
FT                   /evidence="ECO:0000250|UniProtKB:P59868"
SQ   SEQUENCE   33 AA;  3780 MW;  A0042F547B42F946 CRC64;
     ADCLAHLKLC KKNNDCCSKK CSRRGTNPEQ RCR