P-type calcium transporter activity involved in regulation of cardiac muscle cell membrane potential
Definition
Target type: molecularfunction
A calcium-transporting P-type ATPase activity involved in regulation of the plasma membrane potential. [GOC:BHF, GOC:mtg_cardiac_conduct_nov11]
P-type calcium transporters play a crucial role in regulating cardiac muscle cell membrane potential by mediating the active transport of calcium ions across the sarcolemma, the plasma membrane of muscle cells. These transporters, also known as calcium pumps, utilize the energy derived from ATP hydrolysis to move calcium ions against their electrochemical gradient, from the cytoplasm to the extracellular space or into intracellular stores like the sarcoplasmic reticulum. This process is essential for maintaining calcium homeostasis in the cardiomyocytes, which is fundamental for proper heart function.
The movement of calcium ions across the sarcolemma is tightly regulated by a complex interplay of factors, including the membrane potential, the concentration of calcium ions in the cytoplasm and extracellular space, and the activity of various signaling pathways. When a cardiac muscle cell is stimulated, an action potential propagates along the sarcolemma, triggering the opening of voltage-gated calcium channels. This influx of calcium ions into the cytoplasm initiates a cascade of events that ultimately leads to muscle contraction.
P-type calcium transporters play a critical role in terminating this calcium influx and restoring the resting membrane potential. As calcium ions accumulate in the cytoplasm, they bind to the P-type calcium transporter, activating its ATPase activity. This ATPase activity drives the movement of calcium ions out of the cytoplasm, either across the sarcolemma into the extracellular space or into the sarcoplasmic reticulum, where they are stored for later release.
By removing calcium ions from the cytoplasm, P-type calcium transporters contribute to the repolarization of the sarcolemma, restoring the resting membrane potential and preparing the cardiomyocyte for the next cycle of excitation-contraction coupling. The activity of these transporters is also influenced by various signaling pathways, allowing for dynamic regulation of calcium homeostasis in response to changes in physiological demands.
In summary, P-type calcium transporters are key players in the regulation of cardiac muscle cell membrane potential by controlling the influx and efflux of calcium ions. Their activity is essential for maintaining calcium homeostasis, ensuring proper heart function, and enabling the precise and coordinated contraction of cardiac muscle cells.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| Sarcoplasmic/endoplasmic reticulum calcium ATPase 2 | A sarcoplasmic/endoplasmic reticulum calcium ATPase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P16615] | Homo sapiens (human) |
Compounds (5)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 2,5-di-tert-butylhydroquinone | 2,5-di-tert-butylbenzene-1,4-diol : A member of the class of hydroquinones that is benzene-1,4-diol substituted by tert-butyl groups at position 2 and 5. | hydroquinones | |
| paxilline | paxilline : An indole diterpene alkaloid with formula C27H33NO4 isolated from Penicillium paxilli. It is a potent inhibitor of large conductance Ca2(+)- and voltage-activated K(+) (BK)-type channels. paxilline: structure given in first source; RN given refers to (2R-(2alpha,4bbeta,6aalpha,12bbeta,12calpha,14abeta))-isomer | diterpene alkaloid; enone; organic heterohexacyclic compound; terpenoid indole alkaloid; tertiary alcohol | anticonvulsant; Aspergillus metabolite; EC 3.6.3.8 (Ca(2+)-transporting ATPase) inhibitor; genotoxin; geroprotector; mycotoxin; Penicillium metabolite; potassium channel blocker |
| curcumin | curcumin : A beta-diketone that is methane in which two of the hydrogens are substituted by feruloyl groups. A natural dyestuff found in the root of Curcuma longa. Curcumin: A yellow-orange dye obtained from tumeric, the powdered root of CURCUMA longa. It is used in the preparation of curcuma paper and the detection of boron. Curcumin appears to possess a spectrum of pharmacological properties, due primarily to its inhibitory effects on metabolic enzymes. | aromatic ether; beta-diketone; diarylheptanoid; enone; polyphenol | anti-inflammatory agent; antifungal agent; antineoplastic agent; biological pigment; contraceptive drug; dye; EC 1.1.1.205 (IMP dehydrogenase) inhibitor; EC 1.1.1.21 (aldehyde reductase) inhibitor; EC 1.1.1.25 (shikimate dehydrogenase) inhibitor; EC 1.6.5.2 [NAD(P)H dehydrogenase (quinone)] inhibitor; EC 1.8.1.9 (thioredoxin reductase) inhibitor; EC 2.7.10.2 (non-specific protein-tyrosine kinase) inhibitor; EC 3.5.1.98 (histone deacetylase) inhibitor; flavouring agent; food colouring; geroprotector; hepatoprotective agent; immunomodulator; iron chelator; ligand; lipoxygenase inhibitor; metabolite; neuroprotective agent; nutraceutical; radical scavenger |
| biselyngbyaside | biselyngbyaside: antineoplastic from the marine cyanobacterium Lyngbya sp.; structure in first source | ||
| alpha-cyclopiazonic acid | alpha-cyclopiazonic acids |