ID   CM3J_CONMA              Reviewed;          22 AA.
AC   P0DQM8;
DT   07-OCT-2020, integrated into UniProtKB/Swiss-Prot.
DT   07-OCT-2020, sequence version 1.
DT   25-MAY-2022, entry version 5.
DE   RecName: Full=Conotoxin MIIIJ {ECO:0000305|PubMed:32245200};
DE   AltName: Full=AlphaM-MIIIJ {ECO:0000303|PubMed:32245200};
OS   Conus magus (Magical cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Pionoconus.
OX   NCBI_TaxID=6492;
RN   [1]
RP   PROTEIN SEQUENCE, SYNTHESIS, FUNCTION, SUBCELLULAR LOCATION, AND
RP   PYROGLUTAMATE FORMATION AT GLN-1.
RC   TISSUE=Venom;
RX   PubMed=32245200; DOI=10.3390/toxins12030197;
RA   Rybin M.J., O'Brien H., Ramiro I.B.L., Azam L., McIntosh J.M.,
RA   Olivera B.M., Safavi-Hemami H., Yoshikami D.;
RT   "AlphaM-conotoxin MIIIJ blocks nicotinic acetylcholine receptors at
RT   neuromuscular junctions of frog and fish.";
RL   Toxins 12:0-0(2020).
CC   -!- FUNCTION: Probable competitive antagonist of fish muscle acetylcholine
CC       receptor. Inhibits postsynaptic nicotinic acetylcholine receptors
CC       (nAChRs) from fish (zebrafish and goldfish) and frogs (IC(50)=0.1 uM).
CC       Protects these receptors from block by alpha-bungarotoxin and alpha-
CC       conotoxin EI. Does not block nAChRs at the neuromuscular junction of
CC       Rana pipiens. Shows a weak inhibition on mammalian adult and fetal
CC       muscle nAChRs (alpha-1-beta-1-delta-epsilon/CHRNA1-CHRNB1-CHRND-CHRNE
CC       and alpha-1 beta-1 gamma delta/CHRNA1-CHRNB1-CHRNG-CHRND) (IC(50)=3-45
CC       uM). In vivo, induces paralysis in goldfish (Carassius auratus) but not
CC       mice. {ECO:0000269|PubMed:32245200}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:32245200}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC       {ECO:0000305|PubMed:32245200}.
CC   -!- DOMAIN: The cysteine framework is III (CC-C-C-CC). Classified in the M-
CC       1 branch, since 1 residue stands between the fourth and the fifth
CC       cysteine residues. {ECO:0000305}.
CC   -!- MISCELLANEOUS: Does not inhibit mammalian neuronal alpha-3-beta-
CC       4/CHRNA3-CHRNB4, alpha-4-beta-2/CHRNA4-CHRNB2 and alpha-9-alpha-
CC       10/CHRNA9-CHRNA10 nAChRs. {ECO:0000269|PubMed:32245200}.
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; P0DQM8; -.
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:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Direct protein sequencing;
KW   Disulfide bond; Neurotoxin; Postsynaptic neurotoxin;
KW   Pyrrolidone carboxylic acid; Secreted; Toxin.
FT   PEPTIDE         1..22
FT                   /note="Conotoxin MIIIJ"
FT                   /evidence="ECO:0000269|PubMed:32245200"
FT                   /id="PRO_0000450817"
FT   MOD_RES         1
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000269|PubMed:32245200"
FT   DISULFID        3..21
FT                   /evidence="ECO:0000250|UniProtKB:Q5EHP3"
FT   DISULFID        4..19
FT                   /evidence="ECO:0000250|UniProtKB:Q5EHP3"
FT   DISULFID        9..22
FT                   /evidence="ECO:0000250|UniProtKB:Q5EHP3"
SQ   SEQUENCE   22 AA;  2453 MW;  22971518D2855DF2 CRC64;
     QKCCSGGSCP LYFRDRLICP CC