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P-type calcium transporter activity

Definition

Target type: molecularfunction

Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: ATP + H2O + Ca2+(in) = ADP + phosphate + Ca2+(out). [RHEA:18105]

P-type calcium transporter activity is a molecular function characterized by the movement of calcium ions (Ca2+) across cellular membranes against their electrochemical gradient. This process is driven by the hydrolysis of ATP, hence the "P-type" designation, referring to phosphorylation of the transporter protein. These transporters play a critical role in maintaining calcium homeostasis within cells, a process vital for various cellular functions, including muscle contraction, neurotransmission, and cell signaling. The mechanism involves a series of steps: 1) Binding of calcium ions to the transporter's binding site on the intracellular side of the membrane. 2) Phosphorylation of the transporter by ATP, leading to a conformational change. 3) This conformational change exposes the calcium binding site to the extracellular side of the membrane, facilitating calcium release. 4) Dephosphorylation of the transporter restores the initial conformation, allowing for further cycles of calcium transport. P-type calcium transporters are found in a variety of tissues and cell types, with distinct isoforms exhibiting specific properties and functions. For example, the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pumps calcium into the sarcoplasmic reticulum of muscle cells, essential for muscle relaxation. Conversely, plasma membrane Ca2+-ATPase (PMCA) pumps calcium out of the cell, contributing to calcium signal termination and maintaining low intracellular calcium levels. Overall, P-type calcium transporter activity is a fundamental molecular process that ensures proper calcium homeostasis, crucial for the intricate functioning of cells and organisms.'
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Proteins (6)

ProteinDefinitionTaxonomy
Sarcoplasmic/endoplasmic reticulum calcium ATPase 3A sarcoplasmic/endoplasmic reticulum calcium ATPase 3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q93084]Homo sapiens (human)
Sarcoplasmic/endoplasmic reticulum calcium ATPase 2A sarcoplasmic/endoplasmic reticulum calcium ATPase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P16615]Homo sapiens (human)
Sarcoplasmic/endoplasmic reticulum calcium ATPase 1 A sarcoplasmic/endoplasmic reticulum calcium ATPase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O14983]Homo sapiens (human)
Sarcoplasmic/endoplasmic reticulum calcium ATPase 3A sarcoplasmic/endoplasmic reticulum calcium ATPase 3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q93084]Homo sapiens (human)
Sarcoplasmic/endoplasmic reticulum calcium ATPase 2A sarcoplasmic/endoplasmic reticulum calcium ATPase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P16615]Homo sapiens (human)
Sarcoplasmic/endoplasmic reticulum calcium ATPase 1 A sarcoplasmic/endoplasmic reticulum calcium ATPase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O14983]Homo sapiens (human)

Compounds (7)

CompoundDefinitionClassesRoles
2,5-di-tert-butylhydroquinone2,5-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
chelerythrinechelerythrine : A benzophenanthridine alkaloid isolated from the root of Zanthoxylum simulans, Chelidonium majus L., and other Papaveraceae.benzophenanthridine alkaloid;
organic cation
antibacterial agent;
antineoplastic agent;
EC 2.7.11.13 (protein kinase C) inhibitor
paxillinepaxilline : 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
thapsigarginthapsigargin : An organic heterotricyclic compound that is a hexa-oxygenated 6,7-guaianolide isolated fron the roots of Thapsia garganica L., Apiaceae. A potent skin irritant, it is used in traditional medicine as a counter-irritant. Thapsigargin inhibits Ca(2+)-transporting ATPase mediated uptake of calcium ions into sarcoplasmic reticulum and is used in experimentation examining the impacts of increasing cytosolic calcium concentrations.

Thapsigargin: A sesquiterpene lactone found in roots of THAPSIA. It inhibits SARCOPLASMIC RETICULUM CALCIUM-TRANSPORTING ATPASES.
butyrate ester;
organic heterotricyclic compound;
sesquiterpene lactone
calcium channel blocker;
EC 3.6.3.8 (Ca(2+)-transporting ATPase) inhibitor
curcumincurcumin : 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
biselyngbyasidebiselyngbyaside: antineoplastic from the marine cyanobacterium Lyngbya sp.; structure in first source
alpha-cyclopiazonic acidalpha-cyclopiazonic acids