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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
26
|
| pubmed:dateCreated |
1994-7-29
|
| pubmed:databankReference | |
| pubmed:abstractText |
The Na(+)-Ca2+ exchanger is an important regulator of cellular Ca2+ levels, and one isoform of this transporter, NCX1, has been cloned previously (Nicoll, D.A., Longoni, S., and Philipson, K.D. (1990) Science 250, 562-565). We now report the cloning of a second isoform (NCX2) of the Na(+)-Ca2+ exchanger which was present in a rat brain cDNA library. NCX2 is predicted to code for a protein of 921 amino acids. NCX1 and NCX2 are 61 and 65% identical at the nucleotide and amino acid levels, respectively, and are the products of different genes. The genes for NCX1 and NCX2 are located on human chromosomes 2 and 14, respectively. Hydropathy profiles of the two exchangers are very similar. Transcripts of NCX2 are detected in brain and skeletal muscle. NCX2 was expressed in Xenopus oocytes and Na(+)-Ca2+ exchange activity was analyzed electrophysiologically by the giant inside-out, excised patch technique. Outward currents were evoked by the application of Na+ with the exchanger operating in the reversed mode (extracellular Ca2+ exchanging for intracellular Na+). The affinity for Na+ (30 mM) and the current-voltage relationship of NCX2 are similar to those for NCX1. Like NCX1, NCX2 is secondarily regulated by intracellular Ca2+, but the affinity of NCX2 for regulatory Ca2+ (1.5 microM) upon initial application of Na+ is lower than that of NCX1 (0.3 microM). The existence of multiple Na(+)-Ca2+ exchanger isoforms may provide flexibility for regulation and expression.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/DNA, Complementary,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Calcium Exchanger
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jul
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
269
|
| pubmed:geneSymbol |
NCX1,
NCX2
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
17434-9
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:8021246-Amino Acid Sequence,
pubmed-meshheading:8021246-Animals,
pubmed-meshheading:8021246-Base Sequence,
pubmed-meshheading:8021246-Calcium,
pubmed-meshheading:8021246-Carrier Proteins,
pubmed-meshheading:8021246-Chromosome Mapping,
pubmed-meshheading:8021246-Chromosomes, Human, Pair 14,
pubmed-meshheading:8021246-Chromosomes, Human, Pair 2,
pubmed-meshheading:8021246-Cloning, Molecular,
pubmed-meshheading:8021246-DNA, Complementary,
pubmed-meshheading:8021246-Humans,
pubmed-meshheading:8021246-Membrane Potentials,
pubmed-meshheading:8021246-Molecular Sequence Data,
pubmed-meshheading:8021246-Rats,
pubmed-meshheading:8021246-Sequence Homology, Amino Acid,
pubmed-meshheading:8021246-Sodium,
pubmed-meshheading:8021246-Sodium-Calcium Exchanger,
pubmed-meshheading:8021246-Xenopus
|
| pubmed:year |
1994
|
| pubmed:articleTitle |
Cloning of the NCX2 isoform of the plasma membrane Na(+)-Ca2+ exchanger.
|
| pubmed:affiliation |
Department of Physiology, UCLA School of Medicine 90024-1760.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
|