SIX2_MESMA
ID SIX2_MESMA Reviewed; 61 AA.
AC P68727;
DT 07-DEC-2004, integrated into UniProtKB/Swiss-Prot.
DT 07-DEC-2004, sequence version 1.
DT 03-AUG-2022, entry version 56.
DE RecName: Full=Beta-insect depressant toxin BmKIT2;
DE AltName: Full=Depressant insect toxin BmK IT2;
OS Mesobuthus martensii (Manchurian scorpion) (Buthus martensii).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX NCBI_TaxID=34649;
RN [1]
RP PROTEIN SEQUENCE.
RX PubMed=11070192; DOI=10.1016/s0168-0102(00)00164-4;
RA Li Y.-J., Tan Z.-Y., Ji Y.-H.;
RT "The binding of BmK IT2, a depressant insect-selective scorpion toxin on
RT mammal and insect sodium channels.";
RL Neurosci. Res. 38:257-264(2000).
RN [2]
RP FUNCTION.
RX PubMed=7993579;
RA Ji Y.-H., Hattori H., Xu K., Terakawa S.;
RT "Molecular characteristics of four new depressant insect neurotoxins
RT purified from venom of Buthus martensi Karsch by HPLC.";
RL Sci. China, Ser. B, Chem. Life Sci. Earth Sci. 37:955-963(1994).
RN [3]
RP FUNCTION IN ANTIHYPERALGESIA.
RX PubMed=11113589; DOI=10.1016/s0361-9230(00)00355-5;
RA Wang C.-Y., Tan Z.-Y., Chen B., Zhao Z.-Q., Ji Y.-H.;
RT "Antihyperalgesia effect of BmK IT2, a depressant insect-selective scorpion
RT toxin in rat by peripheral administration.";
RL Brain Res. Bull. 53:335-338(2000).
RN [4]
RP FUNCTION IN INHIBITION OF NOCICEPTION.
RX PubMed=11166328; DOI=10.1016/s0028-3908(00)00168-4;
RA Tan Z.-Y., Xiao H., Mao X., Wang C.-Y., Zhao Z.-Q., Ji Y.-H.;
RT "The inhibitory effects of BmK IT2, a scorpion neurotoxin on rat
RT nociceptive flexion reflex and a possible mechanism for modulating voltage-
RT gated Na(+) channels.";
RL Neuropharmacology 40:352-357(2001).
RN [5]
RP FUNCTION IN INHIBITION OF NOCICEPTION.
RX PubMed=13130519; DOI=10.1002/jnr.10723;
RA Zhang X.-Y., Bai Z.-T., Chai Z.-F., Zhang J.-W., Liu Y., Ji Y.-H.;
RT "Suppressive effects of BmK IT2 on nociceptive behavior and c-Fos
RT expression in spinal cord induced by formalin.";
RL J. Neurosci. Res. 74:167-173(2003).
RN [6]
RP FUNCTION.
RX PubMed=16616856; DOI=10.1016/j.phrs.2006.02.009;
RA Chai Z.-F., Bai Z.-T., Liu T., Pang X.-Y., Ji Y.-H.;
RT "The binding of BmK IT2 on mammal and insect sodium channels by surface
RT plasmon resonance assay.";
RL Pharmacol. Res. 54:85-90(2006).
RN [7]
RP FUNCTION IN INHIBITION OF NOCICEPTION.
RX PubMed=17562390; DOI=10.1016/j.brainresbull.2007.03.007;
RA Bai Z.-T., Liu T., Pang X.-Y., Chai Z.-F., Ji Y.-H.;
RT "Suppression by intrathecal BmK IT2 on rat spontaneous pain behaviors and
RT spinal c-Fos expression induced by formalin.";
RL Brain Res. Bull. 73:248-253(2007).
CC -!- FUNCTION: On insects, this depressant beta-toxins cause a transient
CC contraction paralysis followed by a slow flaccid paralysis. They bind
CC voltage-independently at site-4 of sodium channels (Nav) and shift the
CC voltage of activation toward more negative potentials thereby affecting
CC sodium channel activation and promoting spontaneous and repetitive
CC firing. This toxin is active against insects and mammals. It is capable
CC of binding to not only cockroach neuronal membranes, but also rat
CC cerebrocortical and hippocampal synaptosomes. This toxin also has
CC potent peripheral and central suppressive effects on rat nociceptive
CC spontaneous responses, thermal hyperalgesia and spinal c-Fos expression
CC induced by formalin and carrageenan, which may be derived from its
CC modulation on the activity of sodium channels of the neurons.
CC Administration of BmKIT2 into rat brain can also suppress the epileptic
CC seizures significantly. {ECO:0000269|PubMed:11113589,
CC ECO:0000269|PubMed:11166328, ECO:0000269|PubMed:13130519,
CC ECO:0000269|PubMed:16616856, ECO:0000269|PubMed:17562390,
CC ECO:0000269|PubMed:7993579}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR AlphaFoldDB; P68727; -.
DR SMR; P68727; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0006952; P:defense response; IEA:InterPro.
DR CDD; cd00107; Knot1; 1.
DR Gene3D; 3.30.30.10; -; 1.
DR InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR InterPro; IPR003614; Scorpion_toxin-like.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR018218; Scorpion_toxinL.
DR InterPro; IPR002061; Scorpion_toxinL/defensin.
DR Pfam; PF00537; Toxin_3; 1.
DR PRINTS; PR00285; SCORPNTOXIN.
DR SMART; SM00505; Knot1; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
DR PROSITE; PS51863; LCN_CSAB; 1.
PE 1: Evidence at protein level;
KW Amidation; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT CHAIN 1..61
FT /note="Beta-insect depressant toxin BmKIT2"
FT /id="PRO_0000066722"
FT DOMAIN 1..61
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT MOD_RES 61
FT /note="Glycine amide"
FT /evidence="ECO:0000250"
FT DISULFID 10..60
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 14..35
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 21..42
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 25..44
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ SEQUENCE 61 AA; 6650 MW; 961344948E708338 CRC64;
DGYIKGKSGC RVACLIGNQG CLKDCRAYGA SYGYCWTWGL ACWCEGLPDN KTWKSESNTC
G
