SLA_ECHCS
ID SLA_ECHCS Reviewed; 133 AA.
AC P81017;
DT 01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1997, sequence version 1.
DT 25-MAY-2022, entry version 82.
DE RecName: Full=Snaclec echicetin subunit alpha;
OS Echis carinatus sochureki (Saw-scaled viper).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Viperidae; Viperinae; Echis.
OX NCBI_TaxID=124223;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, SUBUNIT, AND SUBCELLULAR LOCATION.
RC TISSUE=Venom;
RX PubMed=9163349; DOI=10.1042/bj3230533;
RA Polgar J., Magnenat E.M., Peitsch M.C., Wells T.N.C., Saqi M.S.A.,
RA Clemetson K.J.;
RT "Amino acid sequence of the alpha subunit and computer modelling of the
RT alpha and beta subunits of echicetin from the venom of Echis carinatus
RT (saw-scaled viper).";
RL Biochem. J. 323:533-537(1997).
RN [2]
RP FUNCTION.
RC TISSUE=Venom;
RX PubMed=8481512;
RA Peng M., Lu W., Beviglia L., Niewiarowski S., Kirby E.P.;
RT "Echicetin: a snake venom protein that inhibits binding of von Willebrand
RT factor and alboaggregins to platelet glycoprotein Ib.";
RL Blood 81:2321-2328(1993).
RN [3]
RP FUNCTION, AND SUBUNIT.
RC TISSUE=Venom;
RX PubMed=11290595; DOI=10.1182/blood.v97.8.2333;
RA Navdaev A., Dormann D., Clemetson J.M., Clemetson K.J.;
RT "Echicetin, a GPIb-binding snake C-type lectin from Echis carinatus, also
RT contains a binding site for IgMkappa responsible for platelet agglutination
RT in plasma and inducing signal transduction.";
RL Blood 97:2333-2341(2001).
CC -!- FUNCTION: Echicetin itself inhibits aggregation of washed platelets
CC induced by vWF, thrombin or alboaggregin-A (PubMed:8481512,
CC PubMed:11290595). However, when complexed with the pentameric plasma
CC immunoglobulin Mkappa (IgMkappa), echicetin binds specifically to GPIb
CC and activates platelets. This is caused by P-selectin expression and
CC activation of alpha-IIb/beta-3 as well as tyrosine phosphorylation of
CC several signal transduction molecules, including p53/56(LYN), p64,
CC p72(SYK), p70 to p90, and p120 (PubMed:11290595). In vivo, it induces
CC thrombocytopenia when injected into mice (PubMed:8481512), probably
CC accounting of activation of platelets rather than inhibition
CC (PubMed:11290595). {ECO:0000269|PubMed:11290595,
CC ECO:0000269|PubMed:8481512, ECO:0000269|PubMed:9163349}.
CC -!- SUBUNIT: Heterodimer of subunits alpha and beta; disulfide-linked
CC (PubMed:9163349). Forms an active complex with the pentameric
CC immunoglobuline Mkappa (IgMkappa) (PubMed:11290595).
CC {ECO:0000269|PubMed:11290595, ECO:0000269|PubMed:9163349}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:9163349}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the snaclec family. {ECO:0000305}.
CC -!- CAUTION: The name echicetin has been given to 2 different proteins,
CC this one from E.carinatus sochureki and another one for which the
CC subspecies has not been specified (E.carinatus). Most experiments have
CC been done on E.carinatus sochureki. {ECO:0000305}.
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DR AlphaFoldDB; P81017; -.
DR SMR; P81017; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR Gene3D; 3.10.100.10; -; 1.
DR InterPro; IPR001304; C-type_lectin-like.
DR InterPro; IPR016186; C-type_lectin-like/link_sf.
DR InterPro; IPR016187; CTDL_fold.
DR Pfam; PF00059; Lectin_C; 1.
DR SMART; SM00034; CLECT; 1.
DR SUPFAM; SSF56436; SSF56436; 1.
DR PROSITE; PS50041; C_TYPE_LECTIN_2; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Disulfide bond; Hemostasis impairing toxin;
KW Platelet aggregation activating toxin; Secreted; Toxin.
FT CHAIN 1..133
FT /note="Snaclec echicetin subunit alpha"
FT /id="PRO_0000046701"
FT DOMAIN 11..128
FT /note="C-type lectin"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00040"
FT DISULFID 4..15
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00040"
FT DISULFID 31..127
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00040"
FT DISULFID 81
FT /note="Interchain (with C-75 in subunit beta)"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00040"
FT DISULFID 102..119
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00040"
SQ SEQUENCE 133 AA; 15803 MW; 8F11C2D0BDC70B16 CRC64;
DQDCLSGWSF YEGHCYQLFR LKTWDEAEKY CNQWDGGHLV SIESNAKAEF VAQLISRKLP
KSAIEDRVWI GLRDRSKREQ CGHLWTDNSF VHYEHVVPPT KCFVLERQTE FRKWIAVNCE
FKFPFVCKAK IPR