Target type: biologicalprocess
Any process that modulates the frequency, rate or extent of striated muscle contraction. [GOC:go_curators]
The regulation of striated muscle contraction is a complex and tightly controlled process that involves a precise interplay of electrical and chemical signals. It begins with a nerve impulse reaching the neuromuscular junction, triggering the release of acetylcholine (ACh). ACh binds to receptors on the muscle fiber membrane (sarcolemma), initiating a depolarization wave. This wave travels down the sarcolemma and into the T-tubules, invaginations of the sarcolemma that run deep into the muscle fiber. The depolarization wave then triggers the release of calcium ions (Ca2+) from the sarcoplasmic reticulum (SR), an extensive network of internal membranes within the muscle fiber. Ca2+ is the key regulator of muscle contraction. With the release of Ca2+, the muscle fiber enters the contraction phase. Ca2+ binds to troponin, a protein complex attached to tropomyosin, which lies on the actin filament. Binding of Ca2+ to troponin causes a conformational change in tropomyosin, moving it away from the myosin binding sites on the actin filament. Now that the binding sites are exposed, myosin heads can bind to actin, forming cross-bridges. The myosin heads then undergo a power stroke, pulling the actin filament towards the center of the sarcomere, the basic contractile unit of a muscle fiber. This process of cross-bridge formation, power stroke, and detachment is repeated as long as Ca2+ remains bound to troponin. As the actin filaments slide past the myosin filaments, the sarcomere shortens, resulting in muscle contraction. When the nerve impulse ceases, ACh is broken down by acetylcholinesterase, ending the depolarization of the sarcolemma. Ca2+ is then actively pumped back into the SR by Ca2+ ATPase pumps, reducing the Ca2+ concentration in the cytoplasm. With reduced Ca2+, troponin returns to its original conformation, and tropomyosin blocks the myosin binding sites on actin. The muscle fiber relaxes as the myosin heads detach from actin, and the sarcomere returns to its resting length. The entire process of muscle contraction and relaxation relies on a delicate balance of calcium ions, ATP, and the proteins involved in the process.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Sodium/potassium-transporting ATPase subunit alpha-2 | A sodium/potassium-transporting ATPase subunit alpha-2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P50993] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| lansoprazole | Lansoprazole: A 2,2,2-trifluoroethoxypyridyl derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. Lansoprazole is a racemic mixture of (R)- and (S)-isomers. | benzimidazoles; pyridines; sulfoxide | anti-ulcer drug; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor |
| 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 | |
| pantoprazole | pantoprazole : A member of the class of benzimidazoles that is 1H-benzimidazole substituted by a difluoromethoxy group at position 5 and a [(3,4-dimethoxypyridin-2-yl)methyl]sulfinyl group at position 2. Pantoprazole: 2-pyridinylmethylsulfinylbenzimidazole proton pump inhibitor that is used in the treatment of GASTROESOPHAGEAL REFLUX and PEPTIC ULCER. | aromatic ether; benzimidazoles; organofluorine compound; pyridines; sulfoxide | anti-ulcer drug; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor; environmental contaminant; xenobiotic |
| digoxigenin | digoxigenin : A hydroxy steroid that consists of 5beta-cardanolide having a double bond at the 20(22)-position as well as hydroxy groups at the 3beta-, 12beta- and 14beta-positions. It has been isolated from the plant species of the genus Digitalis. Digoxigenin: 3 beta,12 beta,14-Trihydroxy-5 beta-card-20(22)-enolide. A cardenolide which is the aglycon of digoxin. Can be obtained by hydrolysis of digoxin or from Digitalis orientalis L. and Digitalis lanata Ehrh. | 12beta-hydroxy steroid; 14beta-hydroxy steroid; 3beta-hydroxy steroid; 3beta-sterol | hapten; plant metabolite |
| digoxigenin-bis(digitoxoside) | cardenolide glycoside | ||
| rostafuroxin | rostafuroxin: structure in first source | ||
| ouabain | cardiac glycoside : Steroid lactones containing sugar residues that act on the contractile force of the cardiac muscles. ouabain : A steroid hormone that is a multi-hydroxylated alpha-L-rhamnosyl cardenoloide. It binds to and inhibits the plasma membrane Na(+)/K(+)-ATPase (sodium pump). It has been isolated naturally from Strophanthus gratus. Ouabain: A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE. | 11alpha-hydroxy steroid; 14beta-hydroxy steroid; 5beta-hydroxy steroid; alpha-L-rhamnoside; cardenolide glycoside; steroid hormone | anti-arrhythmia drug; cardiotonic drug; EC 2.3.3.1 [citrate (Si)-synthase] inhibitor; EC 3.1.3.41 (4-nitrophenylphosphatase) inhibitor; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor; EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor; ion transport inhibitor; plant metabolite |
| digitoxin | digitoxin : A cardenolide glycoside in which the 3beta-hydroxy group of digitoxigenin carries a 2,6-dideoxy-beta-D-ribo-hexopyranosyl-(1->4)-2,6-dideoxy-beta-D-ribo-hexopyranosyl-(1->4)-2,6-dideoxy-beta-D-ribo-hexopyranosyl trisaccharide chain. Digitoxin: A cardiac glycoside sometimes used in place of DIGOXIN. It has a longer half-life than digoxin; toxic effects, which are similar to those of digoxin, are longer lasting. (From Martindale, The Extra Pharmacopoeia, 30th ed, p665) | cardenolide glycoside | EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor |
| digoxin | digoxin : A cardenolide glycoside that is digitoxin beta-hydroxylated at C-12. A cardiac glycoside extracted from the foxglove plant, Digitalis lanata, it is used to control ventricular rate in atrial fibrillation and in the management of congestive heart failure with atrial fibrillation, but the margin between toxic and therapeutic doses is small. Digoxin: A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone DIGOXIGENIN. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in ATRIAL FIBRILLATION and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666) | cardenolide glycoside; steroid saponin | anti-arrhythmia drug; cardiotonic drug; EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor; epitope |
| digitoxigenin | digitoxigenin : A 5beta-cardenolide that is 5beta-cardanolide with hydroxy substituents at the 3beta- and 14beta-positions and double bond unsaturation at C(20)-C(22). Digitoxigenin: 3 beta,14-Dihydroxy-5 beta-card-20(22)enolide. A cardenolide which is the aglycon of digitoxin. Synonyms: Cerberigenin; Echujetin; Evonogenin; Thevetigenin. | 14beta-hydroxy steroid; 3beta-hydroxy steroid | |
| phakellistatin 2 | phakellistatin 2: isolated from the marine sponge Phakellia carteri; structure in first source | ||
| digitoxigenin monodigitoxoside | digitoxigenin monodigitoxoside: RN given refers to (ribo-3beta,5beta)-isomer | ||
| evomonoside | evomonoside : A cardenolide glycoside consisting of digitoxigenin having an alpha-L-rhamnosyl moiety attached at the O(3)-position. evomonoside: a cytotoxic cardiac glycoside from Lepidium apetalum; RN refers to (3beta,5beta)-isomer | cardenolide glycoside | |
| halisulfate 1 | halisulfate 1: an isocitrate lyase inhibitor sesterterpene sulfate from sponge, Hippospongia sp.; structure in first source | organic molecular entity | metabolite |