positive regulation of ryanodine-sensitive calcium-release channel activity
Definition
Target type: biologicalprocess
Any process that increases the activity of a ryanodine-sensitive calcium-release channel. The ryanodine-sensitive calcium-release channel catalyzes the transmembrane transfer of a calcium ion by a channel that opens when a ryanodine class ligand has been bound by the channel complex or one of its constituent parts. [GOC:BHF, GOC:dph, GOC:tb]
Positive regulation of ryanodine-sensitive calcium-release channel activity is a critical biological process involved in the rapid and controlled release of calcium ions from intracellular stores, primarily the sarcoplasmic reticulum (SR) in muscle cells. This release plays a vital role in various physiological functions, including muscle contraction, neurotransmitter release, and hormone secretion. The ryanodine receptor (RyR), a large transmembrane protein complex located on the SR membrane, acts as the calcium release channel.
Here's a detailed breakdown of the process:
1. **Stimulus Reception:** The process is initiated by a stimulus that triggers the release of calcium. These stimuli can vary depending on the cell type and function, but common examples include:
* **Depolarization of the plasma membrane:** In muscle cells, an action potential traveling along the sarcolemma (plasma membrane) triggers the release of calcium from the SR.
* **Hormonal signals:** Hormones like epinephrine or acetylcholine can activate signaling pathways that lead to calcium release.
* **Mechanical stress:** Physical forces, such as stretching, can directly activate RyRs.
2. **Signal Transduction:** Once the stimulus is received, a signaling cascade is activated to relay the signal to the RyR. Key components involved in this cascade include:
* **Dihydropyridine receptor (DHPR):** In muscle cells, the DHPR acts as a voltage sensor on the plasma membrane. It senses the depolarization and interacts with the RyR.
* **Calcium-induced calcium release (CICR):** A small initial influx of calcium can trigger the release of larger amounts of calcium from the SR. This positive feedback loop amplifies the signal.
* **Secondary messengers:** Various intracellular signaling molecules, such as cyclic adenosine monophosphate (cAMP) or inositol trisphosphate (IP3), can influence RyR activity.
3. **RyR Activation:** The signal cascade ultimately activates the RyR, causing a conformational change that opens the calcium release channel. This opening allows calcium ions to flow from the SR into the cytoplasm.
4. **Calcium Release:** The opening of the RyR channel results in a rapid influx of calcium into the cytoplasm. This sudden increase in intracellular calcium concentration triggers downstream effects.
5. **Cellular Response:** The release of calcium from the SR initiates a variety of cellular responses, including:
* **Muscle contraction:** In muscle cells, calcium binds to troponin, a protein that regulates the interaction between actin and myosin filaments, leading to muscle contraction.
* **Neurotransmitter release:** In neurons, calcium influx triggers the fusion of synaptic vesicles with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft.
* **Hormone secretion:** In endocrine cells, calcium release stimulates the exocytosis of hormones, allowing them to be released into the bloodstream.
6. **Calcium Replenishment:** To maintain calcium homeostasis, the SR actively pumps calcium back into its lumen. This process is essential for restoring the SR calcium levels and preparing for subsequent release events.
**Regulation of RyR activity is crucial for proper cellular function. Disruptions in this process can lead to various disorders, including:**
* **Muscle diseases:** Mutations in RyR genes can cause muscle weakness, fatigue, and cramps.
* **Neurological disorders:** Dysregulation of RyR activity can contribute to neurodegenerative diseases and seizures.
* **Cardiac arrhythmias:** Abnormal calcium handling in heart muscle can lead to irregular heartbeats.
Overall, positive regulation of ryanodine-sensitive calcium-release channel activity is a complex and finely-tuned process that plays a fundamental role in the physiology of numerous cell types. Understanding the molecular mechanisms involved in this process is essential for developing therapeutic interventions for various diseases.'
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Proteins (4)
| Protein | Definition | Taxonomy |
|---|---|---|
| Calmodulin | A calmodulin that is encoded in the genome of cow. [PRO:DAN] | Bos taurus (cattle) |
| Glutathione S-transferase omega-1 | A glutathione S-transferase omega-1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P78417] | Homo sapiens (human) |
| Glutathione S-transferase Mu 2 | A glutathione S-transferase mu 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P28161] | Homo sapiens (human) |
| Calmodulin-1 | A calmodulin (human) that is a translation product of the CALM1 gene. [PRO:DAN, UniProtKB:P0DP23] | Homo sapiens (human) |
Compounds (34)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| dinitrochlorobenzene | 1-chloro-2,4-dinitrobenzene : A C-nitro compound that is chlorobenzene carrying a nitro substituent at each of the 2- and 4-positions. Dinitrochlorobenzene: A skin irritant that may cause dermatitis of both primary and allergic types. Contact sensitization with DNCB has been used as a measure of cellular immunity. DNCB is also used as a reagent for the detection and determination of pyridine compounds. | C-nitro compound; monochlorobenzenes | allergen; epitope; sensitiser |
| chlorpromazine | chlorpromazine : A substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropanamine moiety. Chlorpromazine: The prototypical phenothiazine antipsychotic drug. Like the other drugs in this class chlorpromazine's antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking DOPAMINE RECEPTORS. Chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup. | organochlorine compound; phenothiazines; tertiary amine | anticoronaviral agent; antiemetic; dopaminergic antagonist; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; phenothiazine antipsychotic drug |
| ethacrynic acid | etacrynic acid : An aromatic ether that is phenoxyacetic acid in which the phenyl ring is substituted by chlorines at positions 2 and 3, and by a 2-methylidenebutanoyl group at position 4. It is a loop diuretic used to treat high blood pressure resulting from diseases such as congestive heart failure, liver failure, and kidney failure. It is also a glutathione S-transferase (EC 2.5.1.18) inhibitor. Ethacrynic Acid: A compound that inhibits symport of sodium, potassium, and chloride primarily in the ascending limb of Henle, but also in the proximal and distal tubules. This pharmacological action results in excretion of these ions, increased urinary output, and reduction in extracellular fluid. This compound has been classified as a loop or high ceiling diuretic. | aromatic ether; aromatic ketone; dichlorobenzene; monocarboxylic acid | EC 2.5.1.18 (glutathione transferase) inhibitor; ion transport inhibitor; loop diuretic |
| fendiline | Fendiline: Coronary vasodilator; inhibits calcium function in muscle cells in excitation-contraction coupling; proposed as antiarrhythmic and antianginal agents. | diarylmethane | |
| loperamide | loperamide : A synthetic piperidine derivative, effective against diarrhoea resulting from gastroenteritis or inflammatory bowel disease. Loperamide: One of the long-acting synthetic ANTIDIARRHEALS; it is not significantly absorbed from the gut, and has no effect on the adrenergic system or central nervous system, but may antagonize histamine and interfere with acetylcholine release locally. | monocarboxylic acid amide; monochlorobenzenes; piperidines; tertiary alcohol | anticoronaviral agent; antidiarrhoeal drug; mu-opioid receptor agonist |
| omeprazole | 5-methoxy-2-{[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfinyl}-1H-benzimidazole : A member of the class of benzimidazoles that is 1H-benzimidazole which is substituted by a [4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfinyl group at position 2 and a methoxy group at position 5. omeprazole : A racemate comprising equimolar amounts of (R)- and (S)-omeprazole. Omeprazole: A 4-methoxy-3,5-dimethylpyridyl, 5-methoxybenzimidazole derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits an H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. | aromatic ether; benzimidazoles; pyridines; sulfoxide | |
| promethazine | promethazine : A tertiary amine that is a substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropan-2-amine moiety. Promethazine: A phenothiazine derivative with histamine H1-blocking, antimuscarinic, and sedative properties. It is used as an antiallergic, in pruritus, for motion sickness and sedation, and also in animals. | phenothiazines; tertiary amine | anti-allergic agent; anticoronaviral agent; antiemetic; antipruritic drug; H1-receptor antagonist; local anaesthetic; sedative |
| trifluoperazine | N-alkylpiperazine; N-methylpiperazine; organofluorine compound; phenothiazines | antiemetic; calmodulin antagonist; dopaminergic antagonist; EC 1.8.1.12 (trypanothione-disulfide reductase) inhibitor; EC 5.3.3.5 (cholestenol Delta-isomerase) inhibitor; phenothiazine antipsychotic drug | |
| w 7 | W 7: RN given refers to parent cpd; structure; calmodulin antagonist | ||
| diphenylmethane | diphenylmethane : A diarylmethane that is methane substituted by two phenyl groups. | diarylmethane | |
| prenylamine | Prenylamine: A drug formerly used in the treatment of angina pectoris but superseded by less hazardous drugs. Prenylamine depletes myocardial catecholamine stores and has some calcium channel blocking activity. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1406) | diarylmethane | |
| hesperidin | hesperidin : A disaccharide derivative that consists of hesperetin substituted by a 6-O-(alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl moiety at position 7 via a glycosidic linkage. Hesperidin: A flavanone glycoside found in CITRUS fruit peels. | 3'-hydroxyflavanones; 4'-methoxyflavanones; dihydroxyflavanone; disaccharide derivative; flavanone glycoside; monomethoxyflavanone; rutinoside | mutagen |
| flavone | flavone : The simplest member of the class of flavones that consists of 4H-chromen-4-one bearing a phenyl substituent at position 2. flavone: RN given refers to unlabeled cpd; structure given in first source | flavones | metabolite; nematicide |
| 3-hydroxyflavone | 3-hydroxyflavone: structure given in first source flavonol : A monohydroxyflavone that is the 3-hydroxy derivative of flavone. | flavonols; monohydroxyflavone | |
| alpha-tocopherol succinate | hemisuccinate; tocol | ||
| salvin | salvin: a biocyclic diterpenoid; from sage and rosemary (Lamiaceae) | abietane diterpenoid; carbotricyclic compound; catechols; monocarboxylic acid | angiogenesis modulating agent; anti-inflammatory agent; antineoplastic agent; antioxidant; apoptosis inducer; food preservative; HIV protease inhibitor; plant metabolite |
| lubeluzole | lubeluzole: a benzothiazole compound; used for the treatment of acute ischemic stroke; R-91154 is the inactive isomer | benzothiazoles | |
| 6-hydroxyflavone | 6-hydroxyflavone: antioxidant; structure in first source | hydroxyflavonoid | |
| alpha-tocopherol phosphate | alpha-tocopherol phosphate: RN given refers to (2R*(4R*,8R*))-(+-)-isomer | ||
| dioxiram | dioxiram: structure given in first source | ||
| naringenin | (S)-naringenin : The (S)-enantiomer of naringenin. | (2S)-flavan-4-one; naringenin | expectorant; plant metabolite |
| arachidonic acid | arachidonate : A long-chain fatty acid anion resulting from the removal of a proton from the carboxy group of arachidonic acid. icosa-5,8,11,14-tetraenoic acid : Any icosatetraenoic acid with the double bonds at positions 5, 8, 11 and 14. | icosa-5,8,11,14-tetraenoic acid; long-chain fatty acid; omega-6 fatty acid | Daphnia galeata metabolite; EC 3.1.1.1 (carboxylesterase) inhibitor; human metabolite; mouse metabolite |
| N-[3-(N-(2-chloro-1-oxoethyl)-4-nitroanilino)propyl]-2,2,2-trifluoroacetamide | C-nitro compound; secondary carboxamide; tertiary carboxamide; trifluoroacetamide | ||
| 2-(N-(2-chloro-1-oxoethyl)-4-fluoroanilino)-N-cyclohexyl-2-(3-pyridinyl)acetamide | organonitrogen compound; organooxygen compound | ||
| quercetin | 7-hydroxyflavonol; pentahydroxyflavone | antibacterial agent; antineoplastic agent; antioxidant; Aurora kinase inhibitor; chelator; EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor; geroprotector; phytoestrogen; plant metabolite; protein kinase inhibitor; radical scavenger | |
| chrysin | chrysin : A dihydroxyflavone in which the two hydroxy groups are located at positions 5 and 7. | 7-hydroxyflavonol; dihydroxyflavone | anti-inflammatory agent; antineoplastic agent; antioxidant; EC 2.7.11.18 (myosin-light-chain kinase) inhibitor; hepatoprotective agent; plant metabolite |
| 7-hydroxyflavone | 7-hydroxyflavone : A hydroxyflavonoid in which the flavone nucleus is substituted at position 7 by a hydroxy group. | hydroxyflavonoid | |
| 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol | 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol: a specific glutathione S-transferase inhibitor; structure in first source | ||
| carfilzomib | epoxide; morpholines; tetrapeptide | antineoplastic agent; proteasome inhibitor | |
| protoapigenone | protoapigenone: has antineoplastic activity; isolated from Thelypteris torresiana; structure in first source | ||
| shamixanthone | shamixanthone : A pyranoxanthene that is 2,3-dihydropyrano[3,2-a]xanthen-12(1H)-one bearing hydroxy substituents at positions 1 and 11 as well as a prop-1-en-2-yl group at position 2, a methyl substituent at position 5 and a 3,3-dimethylallyl group at position 8. A secondary metabolite produced by Aspergillus nidulans. | cyclic ketone; phenols; pyranoxanthene | metabolite |
| deoxycholic acid, monosodium salt | bile acid salt | ||
| rifampin | Rifampin: A semisynthetic antibiotic produced from Streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits DNA-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1160) | cyclic ketal; hydrazone; N-iminopiperazine; N-methylpiperazine; rifamycins; semisynthetic derivative; zwitterion | angiogenesis inhibitor; antiamoebic agent; antineoplastic agent; antitubercular agent; DNA synthesis inhibitor; EC 2.7.7.6 (RNA polymerase) inhibitor; Escherichia coli metabolite; geroprotector; leprostatic drug; neuroprotective agent; pregnane X receptor agonist; protein synthesis inhibitor |
| clozapine | clozapine : A benzodiazepine that is 5H-dibenzo[b,e][1,4]diazepine substituted by a chloro group at position 8 and a 4-methylpiperazin-1-yl group at position 11. It is a second generation antipsychotic used in the treatment of psychiatric disorders like schizophrenia. Clozapine: A tricylic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2A/2C receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent. | benzodiazepine; N-arylpiperazine; N-methylpiperazine; organochlorine compound | adrenergic antagonist; dopaminergic antagonist; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; environmental contaminant; GABA antagonist; histamine antagonist; muscarinic antagonist; second generation antipsychotic; serotonergic antagonist; xenobiotic |