UniProt functional annotation for P23685



	UniProt functional annotation for P23685

UniProt code: P23685.

Organism: Canis lupus familiaris (Dog) (Canis familiaris).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Laurasiatheria; Carnivora; Caniformia; Canidae; Canis.

Function: Mediates the exchange of one Ca(2+) ion against three to four Na(+) ions across the cell membrane, and thereby contributes to the regulation of cytoplasmic Ca(2+) levels and Ca(2+)-dependent cellular processes (PubMed:1700476, PubMed:1785844, PubMed:9486131, PubMed:17962412). Contributes to Ca(2+) transport during excitation- contraction coupling in muscle. In a first phase, voltage-gated channels mediate the rapid increase of cytoplasmic Ca(2+) levels due to release of Ca(2+) stores from the endoplasmic reticulum. SLC8A1 mediates the export of Ca(2+) from the cell during the next phase, so that cytoplasmic Ca(2+) levels rapidly return to baseline. Required for normal embryonic heart development and the onset of heart contractions (By similarity). {ECO:0000250|UniProtKB:P70414, ECO:0000269|PubMed:1700476, ECO:0000269|PubMed:1785844, ECO:0000269|PubMed:17962412, ECO:0000269|PubMed:19332552, ECO:0000269|PubMed:9486131}.

Activity regulation: Activated by micromolar levels of Ca(2+). In the absence of regulatory Ca(2+), channels open rapidly, and then inactivate rapidly. Inactivation is enhanced by Na(+) and is inhibited by micromolar levels of Ca(2+). {ECO:0000269|PubMed:17962412, ECO:0000269|PubMed:19332552, ECO:0000269|PubMed:9486131}.

Subcellular location: Cell membrane {ECO:0000269|PubMed:1700476, ECO:0000269|PubMed:1785844, ECO:0000269|PubMed:17962412, ECO:0000269|PubMed:19332552, ECO:0000269|PubMed:9486131}; Multi-pass membrane protein {ECO:0000305}. Cell membrane, sarcolemma {ECO:0000269|PubMed:1700476}.

Tissue specificity: Cardiac sarcolemma (at protein level). {ECO:0000269|PubMed:1700476}.

Domain: The cytoplasmic Calx-beta domains bind the regulatory Ca(2+). The first Calx-beta domain can bind up to four Ca(2+) ions (PubMed:16774926, PubMed:19332552, PubMed:22768191). The second domain can bind another two Ca(2+) ions that are essential for calcium- regulated ion exchange (PubMed:17962412). {ECO:0000269|PubMed:16774926, ECO:0000269|PubMed:17962412, ECO:0000269|PubMed:19332552, ECO:0000269|PubMed:22768191}.

Similarity: Belongs to the Ca(2+):cation antiporter (CaCA) (TC 2.A.19) family. SLC8 subfamily. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Canis lupus familiaris (Dog) (Canis familiaris).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Laurasiatheria; Carnivora; Caniformia; Canidae; Canis.



Function:		Mediates the exchange of one Ca(2+) ion against three to four Na(+) ions across the cell membrane, and thereby contributes to the regulation of cytoplasmic Ca(2+) levels and Ca(2+)-dependent cellular processes (PubMed:1700476, PubMed:1785844, PubMed:9486131, PubMed:17962412). Contributes to Ca(2+) transport during excitation- contraction coupling in muscle. In a first phase, voltage-gated channels mediate the rapid increase of cytoplasmic Ca(2+) levels due to release of Ca(2+) stores from the endoplasmic reticulum. SLC8A1 mediates the export of Ca(2+) from the cell during the next phase, so that cytoplasmic Ca(2+) levels rapidly return to baseline. Required for normal embryonic heart development and the onset of heart contractions (By similarity). {ECO:0000250\|UniProtKB:P70414, ECO:0000269\|PubMed:1700476, ECO:0000269\|PubMed:1785844, ECO:0000269\|PubMed:17962412, ECO:0000269\|PubMed:19332552, ECO:0000269\|PubMed:9486131}.


Activity regulation:		Activated by micromolar levels of Ca(2+). In the absence of regulatory Ca(2+), channels open rapidly, and then inactivate rapidly. Inactivation is enhanced by Na(+) and is inhibited by micromolar levels of Ca(2+). {ECO:0000269\|PubMed:17962412, ECO:0000269\|PubMed:19332552, ECO:0000269\|PubMed:9486131}.
Subcellular location:		Cell membrane {ECO:0000269\|PubMed:1700476, ECO:0000269\|PubMed:1785844, ECO:0000269\|PubMed:17962412, ECO:0000269\|PubMed:19332552, ECO:0000269\|PubMed:9486131}; Multi-pass membrane protein {ECO:0000305}. Cell membrane, sarcolemma {ECO:0000269\|PubMed:1700476}.
Tissue specificity:		Cardiac sarcolemma (at protein level). {ECO:0000269\|PubMed:1700476}.
Domain:		The cytoplasmic Calx-beta domains bind the regulatory Ca(2+). The first Calx-beta domain can bind up to four Ca(2+) ions (PubMed:16774926, PubMed:19332552, PubMed:22768191). The second domain can bind another two Ca(2+) ions that are essential for calcium- regulated ion exchange (PubMed:17962412). {ECO:0000269\|PubMed:16774926, ECO:0000269\|PubMed:17962412, ECO:0000269\|PubMed:19332552, ECO:0000269\|PubMed:22768191}.
Similarity:		Belongs to the Ca(2+):cation antiporter (CaCA) (TC 2.A.19) family. SLC8 subfamily. {ECO:0000305}.