ID   TX2M2_LYCSI             Reviewed;         105 AA.
AC   B6DD30;
DT   30-NOV-2010, integrated into UniProtKB/Swiss-Prot.
DT   25-NOV-2008, sequence version 1.
DT   25-MAY-2022, entry version 25.
DE   RecName: Full=U2-lycotoxin-Ls1b {ECO:0000305};
DE            Short=U2-LCTX-Ls1b {ECO:0000305};
DE   AltName: Full=Toxin LSTX-M2 {ECO:0000303|PubMed:19875276};
DE   Flags: Precursor;
OS   Lycosa singoriensis (Wolf spider) (Aranea singoriensis).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Lycosoidea; Lycosidae; Lycosa.
OX   NCBI_TaxID=434756;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=19875276; DOI=10.1016/j.zool.2009.04.001;
RA   Zhang Y., Chen J., Tang X., Wang F., Jiang L., Xiong X., Wang M., Rong M.,
RA   Liu Z., Liang S.;
RT   "Transcriptome analysis of the venom glands of the Chinese wolf spider
RT   Lycosa singoriensis.";
RL   Zoology 113:10-18(2010).
CC   -!- FUNCTION: Insecticidal to house crickets. It induces an excitatory
CC       slow-onset impact that leads to irreversible spastic paralysis. It also
CC       modifies human voltage-gated potassium channel Kv1.5/KCNA5. Most
CC       likely, it binds to the voltage-sensing domain of the channel,
CC       suggesting it does not block the pore but prevents its opening at
CC       physiological membrane potentials. The recombinant peptide binds to the
CC       channel in an irreversible manner and slows down the hKv1.5 current
CC       activation kinetics. It is not toxic to mice, when intracranially
CC       injected (at 0.5 ug/g mouse). {ECO:0000250|UniProtKB:C0HLR8}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:19875276}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:19875276}.
CC   -!- SIMILARITY: Belongs to the neurotoxin 04 (omega-agtx) family. 01 (type
CC       I omega-agtx) subfamily. {ECO:0000305}.
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DR   EMBL; EU926114; ACI41446.1; -; mRNA.
DR   EMBL; FM864118; CAS03715.1; -; mRNA.
DR   AlphaFoldDB; B6DD30; -.
DR   ArachnoServer; AS001053; U2-lycotoxin-Ls1b.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR013605; Toxin_34.
DR   Pfam; PF08396; Toxin_34; 1.
PE   3: Inferred from homology;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Potassium channel impairing toxin; Secreted; Signal; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..17
FT                   /evidence="ECO:0000255"
FT   PROPEP          18..41
FT                   /evidence="ECO:0000305|PubMed:19875276"
FT                   /id="PRO_0000401715"
FT   CHAIN           42..105
FT                   /note="U2-lycotoxin-Ls1b"
FT                   /evidence="ECO:0000305|PubMed:19875276"
FT                   /id="PRO_0000401716"
FT   DISULFID        51..67
FT                   /evidence="ECO:0000250|UniProtKB:C0HLR8"
FT   DISULFID        58..97
FT                   /evidence="ECO:0000250|UniProtKB:C0HLR8"
FT   DISULFID        60..83
FT                   /evidence="ECO:0000250|UniProtKB:C0HLR8"
FT   DISULFID        69..81
FT                   /evidence="ECO:0000250|UniProtKB:C0HLR8"
SQ   SEQUENCE   105 AA;  12141 MW;  EEBD8AAE95A80050 CRC64;
     MIKYVLISAL LVVAVYSFTI EDNEDALLEE AEDELDTEEE RRMALPPGAV CNGHKSDCQC
     FGAKYKCSCP FLWRFRRSAE CHCKKGWAWT AIKKRSCHNR YQWSG