TXC13_CUPSA
ID TXC13_CUPSA Reviewed; 117 AA.
AC P83919; A0A4Y5UGH7; P83920;
DT 16-AUG-2004, integrated into UniProtKB/Swiss-Prot.
DT 07-APR-2021, sequence version 3.
DT 25-MAY-2022, entry version 47.
DE RecName: Full=Neurotoxic enhancer CSTX-13 {ECO:0000303|PubMed:15272079, ECO:0000303|PubMed:15914655};
DE AltName: Full=U2-ctenitoxin-Cs1a {ECO:0000305};
DE Short=U2-CNTX-Cs1a {ECO:0000305};
DE Contains:
DE RecName: Full=CSTX-13 A chain;
DE AltName: Full=U2-ctenitoxin-Cs1a A chain;
DE Short=U2-CNTX-Cs1a A chain;
DE Contains:
DE RecName: Full=CSTX-13 B chain;
DE AltName: Full=U2-ctenitoxin-Cs1a B chain;
DE Short=U2-CNTX-Cs1a B chain;
DE Flags: Precursor;
OS Cupiennius salei (American wandering spider).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC Araneomorphae; Entelegynae; Lycosoidea; Ctenidae; Cupiennius.
OX NCBI_TaxID=6928;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Venom gland;
RX PubMed=30893800; DOI=10.3390/toxins11030167;
RA Kuhn-Nentwig L., Langenegger N., Heller M., Koua D., Nentwig W.;
RT "The dual prey-inactivation strategy of spiders-in-depth venomic analysis
RT of Cupiennius salei.";
RL Toxins 11:0-0(2019).
RN [2]
RP PROTEIN SEQUENCE OF 48-81 AND 88-116, FUNCTION, SUBUNIT, SUBCELLULAR
RP LOCATION, MASS SPECTROMETRY, TOXIC DOSE, AND DISULFIDE BONDS.
RC TISSUE=Venom;
RX PubMed=15272079; DOI=10.1073/pnas.0402226101;
RA Wullschleger B., Kuhn-Nentwig L., Tromp J., Kaempfer U., Schaller J.,
RA Schuerch S., Nentwig W.;
RT "CSTX-13, a highly synergistically acting two-chain neurotoxic enhancer in
RT the venom of the spider Cupiennius salei (Ctenidae).";
RL Proc. Natl. Acad. Sci. U.S.A. 101:11251-11256(2004).
RN [3]
RP FUNCTION.
RX PubMed=15914655; DOI=10.1242/jeb.01594;
RA Wullschleger B., Nentwig W., Kuhn-Nentwig L.;
RT "Spider venom: enhancement of venom efficacy mediated by different
RT synergistic strategies in Cupiennius salei.";
RL J. Exp. Biol. 208:2115-2121(2005).
RN [4]
RP FUNCTION, TOXIC DOSE, SUBUNIT, 3D-STRUCTURE MODELING, AND PROBABLE
RP AMIDATION AT THR-116.
RC TISSUE=Venom;
RX PubMed=32290562; DOI=10.3390/toxins12040250;
RA Clemencon B., Kuhn-Nentwig L., Langenegger N., Kopp L., Peigneur S.,
RA Tytgat J., Nentwig W., Luescher B.P.;
RT "Neurotoxin merging: a strategy deployed by the venom of the spider
RT cupiennius salei to potentiate toxicity on insects.";
RL Toxins 12:0-0(2020).
CC -!- FUNCTION: Synergistic toxin that induces or increases a cytolytic
CC effect when combined with CSTX-1 (AC P81694) or CSTX-9 (AC P58604).
CC When alone, has a weak insecticidal activity, with an unknown molecular
CC target. {ECO:0000269|PubMed:15272079, ECO:0000269|PubMed:15914655}.
CC -!- SUBUNIT: Heterodimer of A and B chains; disulfide-linked
CC (PubMed:15272079). Interacts with CSTX-1 (AC P81694) (Kd=430 nM), and
CC with CSTX-9 (AC P58604) (Kd=370 nM) (PubMed:32290562).
CC {ECO:0000269|PubMed:15272079, ECO:0000269|PubMed:32290562}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:15272079}. Target
CC cell membrane {ECO:0000305|PubMed:32290562}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:15272079}.
CC -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC structurally defines this protein as a knottin.
CC {ECO:0000305|PubMed:15272079}.
CC -!- MASS SPECTROMETRY: [CSTX-13 A chain]: Mass=4342.73;
CC Method=Electrospray; Evidence={ECO:0000269|PubMed:15272079};
CC -!- MASS SPECTROMETRY: [CSTX-13 B chain]: Mass=3475.80;
CC Method=Electrospray; Evidence={ECO:0000269|PubMed:15272079};
CC -!- TOXIC DOSE: LD(50) is 16.3 pmol/mg in Drosophila.
CC {ECO:0000269|PubMed:15272079}.
CC -!- TOXIC DOSE: LD(50) is 111.2 pmol/mg when intrathoracically injected
CC into drosophila. {ECO:0000269|PubMed:32290562}.
CC -!- TOXIC DOSE: LD(50) is 0.075 pmol/mg when intrathoracically co-injected
CC with CSTX-1 (AC P81694) into drosophila. {ECO:0000269|PubMed:32290562}.
CC -!- TOXIC DOSE: LD(50) is 0.082 pmol/mg when intrathoracically co-injected
CC with CSTX-9 (AC P58604) into drosophila. {ECO:0000269|PubMed:32290562}.
CC -!- MISCELLANEOUS: Does not show effect on 18 ion channels: Kv1.1, Kv1.2,
CC Kv1.3, Kv1.4, Kv1.5, Kv1.6, Kv2.1, Kv3.1, Kv4.2, Kv4.3, Shaker IR,
CC hERG, Nav1.2, Nav1.4, Nav1.5, Nav1.6, DmNaV1, and Cav3.3 (when tested
CC at 500 nM on channels expressed in oocytes).
CC {ECO:0000269|PubMed:32290562}.
CC -!- SIMILARITY: Belongs to the neurotoxin 19 (CSTX) family. 12 subfamily.
CC {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 EMBL; MH754552; QDC23087.1; -; mRNA.
DR AlphaFoldDB; P83919; -.
DR SMR; P83919; -.
DR ArachnoServer; AS000210; U2-ctenitoxin-Cs1a.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0019835; P:cytolysis; IEA:UniProtKB-KW.
DR InterPro; IPR019553; Spider_toxin_CSTX_knottin.
DR InterPro; IPR011142; Spider_toxin_CSTX_Knottin_CS.
DR Pfam; PF10530; Toxin_35; 1.
DR PROSITE; PS60029; SPIDER_CSTX; 1.
PE 1: Evidence at protein level;
KW Amidation; Cytolysis; Direct protein sequencing; Disulfide bond; Membrane;
KW Neurotoxin; Secreted; Signal; Target cell membrane; Target membrane; Toxin.
FT SIGNAL 1..20
FT /evidence="ECO:0000255"
FT PROPEP 21..47
FT /evidence="ECO:0000305|PubMed:15272079"
FT /id="PRO_0000452334"
FT PEPTIDE 48..81
FT /note="CSTX-13 A chain"
FT /evidence="ECO:0000269|PubMed:15272079"
FT /id="PRO_0000045011"
FT PROPEP 82..87
FT /evidence="ECO:0000305|PubMed:15272079"
FT /id="PRO_0000452335"
FT PEPTIDE 88..116
FT /note="CSTX-13 B chain"
FT /evidence="ECO:0000269|PubMed:15272079"
FT /id="PRO_0000044560"
FT MOD_RES 116
FT /note="Threonine amide"
FT /evidence="ECO:0000305|PubMed:32290562"
FT DISULFID 50..65
FT /evidence="ECO:0000269|PubMed:15272079"
FT DISULFID 57..74
FT /evidence="ECO:0000269|PubMed:15272079"
FT DISULFID 64..95
FT /note="Interchain (between A and B chains)"
FT /evidence="ECO:0000269|PubMed:15272079"
FT DISULFID 76..93
FT /note="Interchain (between A and B chains)"
FT /evidence="ECO:0000269|PubMed:15272079"
SQ SEQUENCE 117 AA; 13404 MW; AC9FB22D4CEC8045 CRC64;
MKVLVIFAVL SLVIFSNCSA ETDEDFFGEE SFEADDIIPF IAKEQVRSDC TLRNHDCTDD
RHSCCRSKMF KDVCTCFYPS QRSETARAKK ELCTCQQPKH LKYIEKGLQK AKDYATG
