K6TX1_ACTBE
ID K6TX1_ACTBE Reviewed; 17 AA.
AC C0HJD9;
DT 05-DEC-2018, integrated into UniProtKB/Swiss-Prot.
DT 05-DEC-2018, sequence version 1.
DT 25-MAY-2022, entry version 8.
DE RecName: Full=Potassium channel toxin AbeTx1 {ECO:0000303|PubMed:30275388};
OS Actinia bermudensis (Maroon anemone).
OC Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC Actiniidae; Actinia.
OX NCBI_TaxID=1078900;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, MASS SPECTROMETRY, DISULFIDE BOND, AND
RP MUTAGENESIS OF LYS-3; LYS-7; ARG-9; ARG-11 AND LYS-13.
RC TISSUE=Nematoblast;
RX PubMed=30275388; DOI=10.3390/md16100360;
RA Orts D.J.B., Peigneur S., Silva-Goncalves L.C., Arcisio-Miranda M.,
RA Bicudo J.E.P.W., Tytgat J.;
RT "AbeTx1 is a novel sea anemone toxin with a dual mechanism of action on
RT shaker-type K[+] channels activation.";
RL Mar. Drugs 16:1-19(2018).
CC -!- FUNCTION: Potassium channel inhibitor that is the most potent on
CC Kv1.1/KCNA1 (IC(50)=671.95 nM), Kv1.2/KCNA2 (IC(50)=167.36 nM), and
CC Kv1.6/KCNA6 (IC(50)=115.68 nM), and less potent on Kv1.3/KCNA3 (20%
CC inhibition at 3 uM) and on shaker IR (15% inhibition at 3 uM). It
CC inhibits potassium currents, not only by blocking the potassium current
CC of Kv1.2/KCNA2, but by altering the energetics of activation of
CC Kv1.1/KCNA1 and Kv1.6/KCNA6. {ECO:0000269|PubMed:30275388}.
CC -!- SUBCELLULAR LOCATION: Secreted. Nematocyst
CC {ECO:0000269|PubMed:30275388}.
CC -!- DOMAIN: Has the structural arrangement of two alpha-helices stabilized
CC by disulfide bonds (CSalpha/alpha 2(S-S)).
CC {ECO:0000305|PubMed:30275388}.
CC -!- MASS SPECTROMETRY: Mass=1889.8; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:30275388};
CC -!- MISCELLANEOUS: Does not show effect on rNav1.2/SCN2A, rNav1.4/SCN4A and
CC B.germanica Nav1 (BgNav1), rKv1.4/KCNA4, rKv1.5/KCNA4, rKv2.1/KCNB1,
CC hKv3.1/KCNC1, rKv4.2/KCND2, rKv4.3/KCND2, and hKv11.1/ERG1/HERG (3 uM
CC toxin tested). {ECO:0000269|PubMed:30275388}.
CC -!- SIMILARITY: Belongs to the sea anemone type 6 potassium channel toxin
CC family. {ECO:0000305|PubMed:30275388}.
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DR AlphaFoldDB; C0HJD9; -.
DR SMR; C0HJD9; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0042151; C:nematocyst; 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.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Nematocyst; Potassium channel impairing toxin; Secreted; Toxin;
KW Voltage-gated potassium channel impairing toxin.
FT PEPTIDE 1..17
FT /note="Potassium channel toxin AbeTx1"
FT /evidence="ECO:0000269|PubMed:30275388"
FT /id="PRO_0000445909"
FT SITE 1
FT /note="Important residue for binding to potassium channels"
FT /evidence="ECO:0000269|PubMed:30275388"
FT SITE 3
FT /note="Key residue important for binding to potassium
FT channels"
FT /evidence="ECO:0000269|PubMed:30275388"
FT SITE 7
FT /note="Important residue for binding to potassium channels"
FT /evidence="ECO:0000269|PubMed:30275388"
FT SITE 9
FT /note="Important residue for binding to potassium channels"
FT /evidence="ECO:0000269|PubMed:30275388"
FT SITE 11
FT /note="Important residue for binding to potassium channels"
FT /evidence="ECO:0000269|PubMed:30275388"
FT SITE 13
FT /note="Important residue for binding to potassium channels"
FT /evidence="ECO:0000269|PubMed:30275388"
FT DISULFID 2..16
FT /evidence="ECO:0000269|PubMed:30275388"
FT DISULFID 5..10
FT /evidence="ECO:0000269|PubMed:30275388"
FT MUTAGEN 1
FT /note="R->A: 3-fold decrease in potency of inhibition of
FT Kv1.1/KCNA1 and 30-fold decrease in potency of inhibition
FT of Kv1.6/KCNA6."
FT /evidence="ECO:0000269|PubMed:30275388"
FT MUTAGEN 3
FT /note="K->A: 40-fold decrease in potency of inhibition of
FT Kv1.1/KCNA1 and 160-fold decrease in potency of inhibition
FT of Kv1.6/KCNA6."
FT /evidence="ECO:0000269|PubMed:30275388"
FT MUTAGEN 7
FT /note="K->A: 26-fold decrease in potency of inhibition of
FT Kv1.1/KCNA1 and 7-fold decrease in potency of inhibition of
FT Kv1.6/KCNA6."
FT /evidence="ECO:0000269|PubMed:30275388"
FT MUTAGEN 9
FT /note="R->A: 12-fold decrease in potency of inhibition of
FT Kv1.1/KCNA1 and 21-fold decrease in potency of inhibition
FT of Kv1.6/KCNA6."
FT /evidence="ECO:0000269|PubMed:30275388"
FT MUTAGEN 11
FT /note="R->A: 32-fold decrease in potency of inhibition of
FT Kv1.1/KCNA1 and 7-fold decrease in potency of inhibition of
FT Kv1.6/KCNA6."
FT /evidence="ECO:0000269|PubMed:30275388"
FT MUTAGEN 13
FT /note="K->A: 7-fold decrease in potency of inhibition of
FT Kv1.1/KCNA1 and 9-fold decrease in potency of inhibition of
FT Kv1.6/KCNA6."
FT /evidence="ECO:0000269|PubMed:30275388"
SQ SEQUENCE 17 AA; 1894 MW; 39FE97B6EEE828FB CRC64;
RCKTCSKGRC RPKPNCG
