P60252 · CAOP1_OPICA
- ProteinOpicalcin-1
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
This toxin stabilizes ryanodine receptor 1 (RyR1) opening in a long-lasting subconductance state (35% of the full conductance state) (PubMed:27114612).
Furthermore, it triggers calcium release from sarcoplasmic vesicles (2 nM are enough to induce a sharp release, and 67% of the total calcium is released after toxin (100 nM) addition) probably by acting as a cell-penetrating peptide (CPP) (PubMed:27114612).
In addition, it has been shown to dose-dependently stimulate ryanodine binding to RyR1 (EC50=0.3 nM) (PubMed:27114612).
It also augments the bell-shaped calcium-[3H]ryanodine binding curve that is maximal at about 10 uM calcium concentration (PubMed:27114612).
It binds a different site as ryanodine (By similarity).
It acts synergistically with caffeine (By similarity).
In vivo, intracerebroventricular injection into mice induces neurotoxic symptoms, followed by death (By similarity).
Furthermore, it triggers calcium release from sarcoplasmic vesicles (2 nM are enough to induce a sharp release, and 67% of the total calcium is released after toxin (100 nM) addition) probably by acting as a cell-penetrating peptide (CPP) (PubMed:27114612).
In addition, it has been shown to dose-dependently stimulate ryanodine binding to RyR1 (EC50=0.3 nM) (PubMed:27114612).
It also augments the bell-shaped calcium-[3H]ryanodine binding curve that is maximal at about 10 uM calcium concentration (PubMed:27114612).
It binds a different site as ryanodine (By similarity).
It acts synergistically with caffeine (By similarity).
In vivo, intracerebroventricular injection into mice induces neurotoxic symptoms, followed by death (By similarity).
Features
Showing features for site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 64 | Essential for stimulation of [3H]ryanodine binding to RYR1 | ||||
Sequence: R | ||||||
Site | 66 | Essential for stimulation of [3H]ryanodine binding to RYR1 | ||||
Sequence: R |
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Molecular Function | calcium channel inhibitor activity | |
Molecular Function | toxin activity |
Keywords
- Molecular function
Names & Taxonomy
Protein names
- Recommended nameOpicalcin-1
- Short namesOpCa1
- Alternative names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Ecdysozoa > Arthropoda > Chelicerata > Arachnida > Scorpiones > Iurida > Scorpionoidea > Scorpionidae > Opistophthalminae > Opistophthalmus
Accessions
- Primary accessionP60252
Subcellular Location
PTM/Processing
Features
Showing features for signal, propeptide, chain, disulfide bond.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-22 | |||||
Sequence: MKPSLIIVTFIVVFMAISCVAA | ||||||
Propeptide | PRO_0000035351 | 23-31 | ||||
Sequence: DDEQETWIE | ||||||
Chain | PRO_0000035352 | 34-66 | Opicalcin-1 | |||
Sequence: GDCLPHLKRCKENNDCCSKKCKRRGTNPEKRCR | ||||||
Disulfide bond | 36↔50 | |||||
Sequence: CLPHLKRCKENNDCC | ||||||
Disulfide bond | 43↔54 | |||||
Sequence: CKENNDCCSKKC | ||||||
Disulfide bond | 49↔65 | |||||
Sequence: CCSKKCKRRGTNPEKRC |
Keywords
- PTM
Expression
Tissue specificity
Expressed by the venom gland.
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 55-57 | Essential for stimulation of [3H]ryanodine binding to RYR1 | ||||
Sequence: KRR |
Domain
The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin.
Sequence similarities
Belongs to the scorpion calcin family.
Keywords
- Domain
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length66
- Mass (Da)7,644
- Last updated2004-01-16 v1
- Checksum2CC7799E9F3AEF41