Plasma membrane-type Ca2+-ATPases (PMCAs) mediate the export of bivalent calcium ions from eukaryotic cells. As members of the P class of ion-motive ATPases, PMCAs are a functionally diverse group of proteins that are derived from alternatively spliced transcripts originating from four distinct genes, PMCA1, 2, 3, and 4. The expression of different PMCA isoforms and splice variants is regulated in a developmental, tissue- and cell type-specific manner, and with respect to the physiological needs of specific cell and tissue types. Spatial and temporal rates of resting intracellular Ca2+ concentrations and Ca2+ signaling in eukaryotic cells are dependent on the array of PMCA isoforms that are expressed in concert with the rate of Ca2+ export. PMCA3 expression is confined to brain and skeletal muscle. The PMCA4 gene is located on human chromosome 1q25 and is ubiquitously expressed.
Function:
This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the transport of calcium out of the cell.
Subcellular Location:
Cell membrane; Multi-pass membrane protein.
Tissue Specificity:
Isoform XB is the most abundant isoform and is expressed ubiquitously. Isoforms containing segment Z have only been detected in heart, while isoforms containing segment a have been found in heart, stomach and brain cortex.
Similarity:
Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIB subfamily.
SWISS:
P23634
Gene ID:
493
Database links:
Entrez Gene: 282146 Cow
Entrez Gene: 493 Human
Entrez Gene: 381290 Mouse
Entrez Gene: 733701 Pig
Entrez Gene: 29600 Rat
Omim: 108732 Human
SwissProt: P23634 Human
SwissProt: Q32ME1 Mouse
SwissProt: Q64542 Rat
Unigene: 343522 Human
Unigene: 9986 Rat
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