ID   CM3E_CONPI              Reviewed;          74 AA.
AC   P0C7I1;
DT   29-APR-2008, integrated into UniProtKB/Swiss-Prot.
DT   29-APR-2008, sequence version 1.
DT   25-MAY-2022, entry version 35.
DE   RecName: Full=Psi-conotoxin PrIIIE;
DE   AltName: Full=Psi-conotoxin Pr3.5;
DE   AltName: Full=Psi-conotoxin pr3e;
DE   Flags: Precursor;
OS   Conus parius (Cone snail).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Phasmoconus.
OX   NCBI_TaxID=505247;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], SYNTHESIS OF 51-72, AMIDATION AT CYS-72, AND
RP   FUNCTION.
RC   TISSUE=Venom duct;
RX   PubMed=18054976; DOI=10.1016/j.toxicon.2007.07.009;
RA   Lluisma A.O., Lopez-Vera E., Bulaj G., Watkins M., Olivera B.M.;
RT   "Characterization of a novel psi-conotoxin from Conus parius Reeve.";
RL   Toxicon 51:174-180(2008).
CC   -!- FUNCTION: Psi-conotoxins act on postsynaptic membranes, and act as non-
CC       competitive antagonist of nicotinic acetylcholine receptors (nAChR).
CC       Reversibly inhibits both adult- and fetal-types nAChR. The inhibition
CC       potency against the adult- (alpha-1/beta-1/epsilon/delta) is higher
CC       than against the fetal-type (alpha-1/beta-1/gamma/delta). Induces
CC       flaccid paralysis in goldfish, but does not induce any remarkable
CC       behavior in mice and does not block action potential in directly
CC       stimulated frog muscle preparations. {ECO:0000269|PubMed:18054976}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC   -!- DOMAIN: The cysteine framework is III (CC-C-C-CC). Classified in the M-
CC       4 branch, since 4 residues stand between the fourth and the fifth
CC       cysteine residues.
CC   -!- MISCELLANEOUS: Does not show inhibitory effects against the mouse
CC       muscle subtype sodium channel Nav1.4/SCN4A.
CC       {ECO:0000305|PubMed:18054976}.
CC   -!- SIMILARITY: Belongs to the conotoxin M superfamily. {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   AlphaFoldDB; P0C7I1; -.
DR   ConoServer; 2831; PrIIIE precursor.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0035792; C:host cell postsynaptic membrane; IEA:UniProtKB-KW.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR004214; Conotoxin.
DR   Pfam; PF02950; Conotoxin; 1.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Amidation;
KW   Cleavage on pair of basic residues; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Postsynaptic neurotoxin; Secreted;
KW   Signal; Toxin.
FT   SIGNAL          1..19
FT                   /evidence="ECO:0000255"
FT   PROPEP          20..50
FT                   /evidence="ECO:0000305"
FT                   /id="PRO_0000331766"
FT   PEPTIDE         51..72
FT                   /note="Psi-conotoxin PrIIIE"
FT                   /id="PRO_0000331767"
FT   MOD_RES         72
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000305|PubMed:18054976"
FT   DISULFID        54..66
FT                   /evidence="ECO:0000250|UniProtKB:P01523"
FT   DISULFID        55..71
FT                   /evidence="ECO:0000250|UniProtKB:P01523"
FT   DISULFID        61..72
FT                   /evidence="ECO:0000250|UniProtKB:P01523"
SQ   SEQUENCE   74 AA;  8446 MW;  6E4C4B9116A7824C CRC64;
     MSKLGVLLTI CLLLFPITAL PVDGDQPADR PVERMQDNIS SEQHPFFEKR AARCCTYHGS
     CLKEKCRRKY CCGR