TX21A_PHONI
ID TX21A_PHONI Reviewed; 34 AA.
AC P81789;
DT 23-JAN-2002, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2002, sequence version 1.
DT 23-FEB-2022, entry version 52.
DE RecName: Full=Omega-ctenitoxin-Pn2a {ECO:0000305};
DE Short=Omega-CNTX-Pn2a {ECO:0000305};
DE AltName: Full=Neurotoxin Tx3-3 {ECO:0000303|PubMed:16278100, ECO:0000303|PubMed:8446961, ECO:0000303|PubMed:8660275};
DE AltName: Full=Omega-PnTx3-3 {ECO:0000303|PubMed:10884557};
DE Short=PnTx3-3 {ECO:0000303|PubMed:16278100};
DE Flags: Fragment;
OS Phoneutria nigriventer (Brazilian armed spider) (Ctenus nigriventer).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC Araneomorphae; Entelegynae; Lycosoidea; Ctenidae; Phoneutria.
OX NCBI_TaxID=6918;
RN [1]
RP PROTEIN SEQUENCE.
RC TISSUE=Venom;
RX PubMed=8446961; DOI=10.1016/0041-0101(93)90354-l;
RA Cordeiro M.N., De Figueiredo S.G., Valentim A.D.C., Diniz C.R.,
RA von Eickstedt V.R.D., Gilroy J., Richardson M.;
RT "Purification and amino acid sequences of six Tx3 type neurotoxins from the
RT venom of the Brazilian 'armed' spider Phoneutria nigriventer (Keys).";
RL Toxicon 31:35-42(1993).
RN [2]
RP PROTEIN SEQUENCE OF 1-32, AND SUBCELLULAR LOCATION.
RC TISSUE=Venom;
RX PubMed=16278100; DOI=10.1016/j.cbpc.2005.09.010;
RA Richardson M., Pimenta A.M., Bemquerer M.P., Santoro M.M., Beirao P.S.,
RA Lima M.E., Figueiredo S.G., Bloch C. Jr., Vasconcelos E.A., Campos F.A.,
RA Gomes P.C., Cordeiro M.N.;
RT "Comparison of the partial proteomes of the venoms of Brazilian spiders of
RT the genus Phoneutria.";
RL Comp. Biochem. Physiol. 142:173-187(2006).
RN [3]
RP FUNCTION.
RC TISSUE=Venom;
RX PubMed=8660275; DOI=10.1042/bj3140145;
RA Prado M.A.M., Guatimosim C., Gomez M.V., Diniz C.R., Cordeiro M.N.,
RA Romano-Silva M.A.;
RT "A novel tool for the investigation of glutamate release from rat
RT cerebrocortical synaptosomes: the toxin Tx3-3 from the venom of the spider
RT Phoneutria nigriventer.";
RL Biochem. J. 314:145-150(1996).
RN [4]
RP FUNCTION.
RC TISSUE=Venom;
RX PubMed=9351520; DOI=10.1038/sj.bjp.0701381;
RA Guatimosim C., Romano-Silva M.A., Cruz J.S., Beirao P.S.L.,
RA Kalapothakis E., Moraes-Santos T., Cordeiro M.N., Diniz C.R., Gomez M.V.,
RA Prado M.A.M.;
RT "A toxin from the spider Phoneutria nigriventer that blocks calcium
RT channels coupled to exocytosis.";
RL Br. J. Pharmacol. 122:591-597(1997).
RN [5]
RP FUNCTION.
RC TISSUE=Venom;
RX PubMed=9631431; DOI=10.1097/00001756-199805110-00022;
RA Miranda D.M., Romano-Silva M.A., Kalapothakis E., Diniz C.R.,
RA Cordeiro M.N., Santos T.M., Prado M.A.M., Gomez M.V.;
RT "Phoneutria nigriventer toxins block tityustoxin-induced calcium influx in
RT synaptosomes.";
RL NeuroReport 9:1371-1373(1998).
RN [6]
RP FUNCTION.
RC TISSUE=Venom;
RX PubMed=10884557; DOI=10.1016/s0028-3908(99)00267-1;
RA Leao R.M., Cruz J.S., Diniz C.R., Cordeiro M.N., Beirao P.S.L.;
RT "Inhibition of neuronal high-voltage activated calcium channels by the
RT omega-Phoneutria nigriventer Tx3-3 peptide toxin.";
RL Neuropharmacology 39:1756-1767(2000).
RN [7]
RP FUNCTION.
RC TISSUE=Venom;
RX PubMed=11397544; DOI=10.1016/s0361-9230(01)00443-9;
RA Miranda D.M., Romano-Silva M.A., Kalapothakis E., Diniz C.R.,
RA Cordeiro M.N., Moraes-Santos T., De Marco L.A., Prado M.A.M., Gomez M.V.;
RT "Spider neurotoxins block the beta scorpion toxin-induced calcium uptake in
RT rat brain cortical synaptosomes.";
RL Brain Res. Bull. 54:533-536(2001).
RN [8]
RP FUNCTION.
RX PubMed=19370546; DOI=10.1002/hipo.20580;
RA Pinheiro A.C., da Silva A.J., Prado M.A., Cordeiro M.D., Richardson M.,
RA Batista M.C., de Castro Junior C.J., Massensini A.R., Guatimosim C.,
RA Romano-Silva M.A., Kushmerick C., Gomez M.V.;
RT "Phoneutria spider toxins block ischemia-induced glutamate release,
RT neuronal death, and loss of neurotransmission in hippocampus.";
RL Hippocampus 19:1123-1129(2009).
CC -!- FUNCTION: Inhibits all known high-voltage activated calcium channels
CC (L-, P/Q- and R-type currents) (Cav), and most effectively the
CC P/Q- (Cav2.1/CACNA1A) and R-type (Cav2.3/CACNA1E) currents
CC (PubMed:10884557). In rat brain, inhibits glutamate release, neuronal
CC death and loss of neurotransmission in the hippocampus resulting from
CC ischemia. In vivo, induces rapid general flaccid paralysis followed by
CC death in 10-30 minutes at dose levels of 5 ug per mouse.
CC {ECO:0000269|PubMed:10884557, ECO:0000269|PubMed:11397544,
CC ECO:0000269|PubMed:19370546, ECO:0000269|PubMed:8660275,
CC ECO:0000269|PubMed:9351520, ECO:0000269|PubMed:9631431}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:16278100}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:16278100}.
CC -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC structurally defines this protein as a knottin. {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the neurotoxin 02 (plectoxin) family. 01 (Tx3)
CC subfamily. {ECO:0000305}.
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DR PIR; C44336; C44336.
DR ArachnoServer; AS000261; omega-ctenitoxin-Pn2a.
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:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE 1: Evidence at protein level;
KW Calcium channel impairing toxin; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Knottin; Neurotoxin; Secreted; Toxin;
KW Voltage-gated calcium channel impairing toxin.
FT CHAIN 1..>34
FT /note="Omega-ctenitoxin-Pn2a"
FT /evidence="ECO:0000305|PubMed:8446961"
FT /id="PRO_0000087634"
FT DISULFID 2..16
FT /evidence="ECO:0000250"
FT DISULFID 9..26
FT /evidence="ECO:0000250"
FT DISULFID 15..28
FT /evidence="ECO:0000250"
FT NON_TER 34
FT /evidence="ECO:0000305|PubMed:8446961"
SQ SEQUENCE 34 AA; 3700 MW; 59E90E00D78A4260 CRC64;
GCANAYKSCN GPHTCCWGYN GYKKACICSG XNWK
