Q91055 (CRVP_HELHO) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Cysteine-rich venom protein helothermine Short name=CRVP HLTx
Organism	Heloderma horridum horridum (Mexican beaded lizard)
Taxonomic identifier	8552 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Sauropsida › Sauria › Lepidosauria › Squamata › Scleroglossa › Anguimorpha › Helodermatidae › Heloderma › Heloderma horridum

Protein attributes

Sequence length	242 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Alters a variety of ion channel activities, including voltage-gated potassium channels (Kv) (Ref.3), voltage-gated calcium channels (L-, N-, and P-type) (Cav) (Ref.4) and ryanodine receptors (RyR) (Ref.1). Is toxic to mice (causes lethargy, partial paralysis of rear limbs and lowering of body temperature). Ref.1 Ref.3 Ref.4
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Miscellaneous	IC50=0.52 µM on IA-type current, and 0.86 µM on delayed rectifier current (Ref.3).
Sequence similarities	Belongs to the CRISP family. Contains 1 SCP domain.

Ontologies

Keywords
Cellular component	Secreted
Domain	Signal
Molecular function	Calcium channel inhibitor Ion channel impairing toxin Neurotoxin Potassium channel inhibitor Toxin
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Cellular_component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	calcium channel inhibitor activity Inferred from electronic annotation. Source: UniProtKB-KW potassium channel inhibitor activity Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 19	19	Ref.2
	Chain	20 – 242	223	Cysteine-rich venom protein helothermine		PRO_0000006272
Regions
	Domain	41 – 169	129	SCP
Amino acid modifications
	Disulfide bond	77 ↔ 155		By similarity
	Disulfide bond	94 ↔ 170		By similarity
	Disulfide bond	150 ↔ 167		By similarity
	Disulfide bond	189 ↔ 196		By similarity
	Disulfide bond	192 ↔ 201		By similarity
	Disulfide bond	205 ↔ 237		By similarity
	Disulfide bond	214 ↔ 231		By similarity
	Disulfide bond	223 ↔ 235		By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q91055 [UniParc]. Last modified November 1, 1996. Version 1. Checksum: 0E183FC2F925DF3C	FASTA	242	27,493
	10 20 30 40 50 60 MILLSLYLCL AAMLHQSEGE ASPKLPGLMT SNPDQQTEIT DKHNNLRRIV EPTASNMLKM 70 80 90 100 110 120 TWSNKIAQNA QRSANQCTLE HTSKEERTID GVECGENLFF SSAPYTWSYA IQNWFDERKY 130 140 150 160 170 180 FRFNYGPTAQ NVMIGHYTQV VWYRSYELGC AIAYCPDQPT YKYYQVCQYC PGGNIRSRKY 190 200 210 220 230 240 TPYSIGPPCG DCPDACDNGL CTNPCKQNDV YNNCPDLKKQ VGCGHPIMKD CMATCKCLTE IK

References

[1]	"Primary structure and properties of helothermine, a peptide toxin that blocks ryanodine receptors." Morrissette J., Kraetzschmar J., Haendler B., El-Hayek R., Mochca-Morales J., Martin B.M., Patel J.R., Moss R.L., Schleuning W.-D., Coronado R., Possani L.D. Biophys. J. 68:2280-2288(1995) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], PARTIAL PROTEIN SEQUENCE, FUNCTION.
[2]	"Isolation and characterization of helothermine, a novel toxin from Heloderma horridum horridum (Mexican beaded lizard) venom." Mochca-Morales J., Martin B.M., Possani L.D. Toxicon 28:299-309(1990) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 20-39, CHARACTERIZATION. Tissue: Venom.
[3]	"The toxin helothermine affects potassium currents in newborn rat cerebellar granule cells." Nobile M., Magnelli V., Lagostena L., Mochca-Morales J., Possani L.D., Prestipino G. J. Membr. Biol. 139:49-55(1994) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION.
[4]	"Helothermine, a lizard venom toxin, inhibits calcium current in cerebellar granules." Nobile M., Noceti F., Prestipino G., Possani L.D. Exp. Brain Res. 110:15-20(1996) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION.

Cross-references

Sequence databases
EMBL GenBank DDBJ	U13619 mRNA. Translation: AAC59730.1.
PIR	A34859.
3D structure databases
ProteinModelPortal	Q91055.
SMR	Q91055. Positions 34-241.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Phylogenomic databases
HOVERGEN	HBG004184.
Family and domain databases
Gene3D	3.40.33.10. 1 hit.
InterPro	IPR001283. Allrgn_V5/Tpx1. IPR018244. Allrgn_V5/Tpx1_CS. IPR014044. CAP_domain. IPR013871. Cysteine_rich_secretory. [Graphical view]
PANTHER	PTHR10334. PTHR10334. 1 hit.
Pfam	PF00188. CAP. 1 hit. PF08562. Crisp. 1 hit. [Graphical view]
PRINTS	PR00837. V5TPXLIKE.
SMART	SM00198. SCP. 1 hit. [Graphical view]
SUPFAM	SSF55797. SCP-like_extracellular. 1 hit.
PROSITE	PS01009. CRISP_1. 1 hit. PS01010. CRISP_2. False negative. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CRVP_HELHO

Accession

Primary (citable) accession number: Q91055
Secondary accession number(s): P46693

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	November 1, 1996
Last modified:	May 1, 2013
This is version 66 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program

Annotation program

Chordata Protein Annotation Program