ID   TX21A_PLETR             Reviewed;          77 AA.
AC   P0DL38;
DT   04-FEB-2015, integrated into UniProtKB/Swiss-Prot.
DT   04-FEB-2015, sequence version 1.
DT   25-MAY-2022, entry version 12.
DE   RecName: Full=Delta/omega-plectoxin-Pt1a {ECO:0000303|PubMed:23691198};
DE            Short=Delta/omega-PLTX-Pt1a;
DE   Flags: Precursor;
OS   Plectreurys tristis (Spider) (Plectreurys bispinosus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Haplogynae; Pholcoidea; Plectreuridae; Plectreurys.
OX   NCBI_TaxID=33319;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 35-72, FUNCTION,
RP   IDENTIFICATION BY MASS SPECTROMETRY, SUBCELLULAR LOCATION, PALMITOYLATION
RP   AT SER-73, AND AMIDATION AT CYS-74.
RC   TISSUE=Venom, and Venom gland;
RX   PubMed=23691198; DOI=10.1371/journal.pone.0064324;
RA   Zhou Y., Zhao M., Fields G.B., Wu C.F., Branton W.D.;
RT   "delta/omega-Plectoxin-Pt1a: an excitatory spider toxin with actions on
RT   both Ca(2+) and Na(+) channels.";
RL   PLoS ONE 8:E64324-E64324(2013).
CC   -!- FUNCTION: Excitatory toxin that acts on both calcium and sodium (Nav)
CC       channels. It preferentially blocks a subset of calcium channels that is
CC       apparently not required for neurotransmitter release, it decreases
CC       threshold for sodium channel activation and it slows sodium channel
CC       inactivation. As it enhances synaptic transmission by prolonging
CC       presynaptic release of neurotransmitter, its effects on sodium and
CC       calcium channels may act synergistically to sustain the terminal
CC       excitability. {ECO:0000269|PubMed:23691198}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:23691198}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:23691198}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000305}.
CC   -!- MISCELLANEOUS: Has no significant effect on voltage-gated potassium
CC       current in Drosophila giant neurons. {ECO:0000269|PubMed:23691198}.
CC   -!- SIMILARITY: Belongs to the neurotoxin 02 (plectoxin) family. 01 (Tx3)
CC       subfamily.
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DR   AlphaFoldDB; P0DL38; -.
DR   SMR; P0DL38; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005246; F:calcium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0017080; F:sodium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Amidation; Calcium channel impairing toxin; Direct protein sequencing;
KW   Disulfide bond; Ion channel impairing toxin; Knottin; Lipoprotein;
KW   Neurotoxin; Palmitate; Presynaptic neurotoxin; Secreted; Signal; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000255"
FT   PROPEP          21..34
FT                   /evidence="ECO:0000269|PubMed:23691198"
FT                   /id="PRO_0000431731"
FT   CHAIN           35..74
FT                   /note="Delta/omega-plectoxin-Pt1a"
FT                   /id="PRO_0000431732"
FT   MOD_RES         74
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000269|PubMed:23691198"
FT   LIPID           73
FT                   /note="O-palmitoyl serine"
FT                   /evidence="ECO:0000269|PubMed:23691198"
FT   DISULFID        38..51
FT                   /evidence="ECO:0000250|UniProtKB:P36983"
FT   DISULFID        45..57
FT                   /evidence="ECO:0000250|UniProtKB:P36983"
FT   DISULFID        50..67
FT                   /evidence="ECO:0000250|UniProtKB:P36983"
FT   DISULFID        54..74
FT                   /evidence="ECO:0000250|UniProtKB:P36983"
FT   DISULFID        59..65
FT                   /evidence="ECO:0000250|UniProtKB:P36983"
SQ   SEQUENCE   77 AA;  8536 MW;  04182C87B4D172B3 CRC64;
     MKHLIVAVVL LSALAICTSA EEEQVNVPFR PEERIGECAG WNDNCDKRSC CDQCHQCRCK
     FGSNCRCTGT KPSCGKR