Molecular studies of the cardiac sarcolemmal sodium-calcium exchanger.
The molecular nature of the canine cardiac sarcolemmal Na(+)-Ca2+ exchanger has been investigated by purification of the protein and by sequencing and expression of an exchanger cDNA clone. The mature exchanger protein is apparently 120 kDa, with glycosylation at a single asparagine residue near the amino terminus. A proposed model for the exchanger protein includes 11 transmembrane segments, a large cytoplasmic domain that is not involved in ion translocation, an exchanger inhibitory site, two Ca2+ interaction sites and an ion-translocation pathway. Experiments are now under way to test the proposed model.
Nicoll
D A
DA
Department of Medicine, University of California, Los Angeles.
Philipson
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KD
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D003001:Cloning, Molecular; D004285:Dogs; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D011487:Protein Conformation; D012508:Sarcolemma / Q000378:metabolism*; D016415:Sequence Alignment; D012964:Sodium / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger
D002352:Carrier Proteins; D019831:Sodium-Calcium Exchanger; D012964:Sodium; D002118:Calcium