SLC24A1 exchanges 4Na+ for Ca2+, K+

Stable Identifier
Reaction [transition]
Homo sapiens
NCKX1 removes Ca2+ from the rod outer segment
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Intracellular Ca2+ is extruded from the outer segment by a Na+/Ca2+, K+ exchanger (NCKX1 encoded by SLC24A1) (Tucker et al. 1998). Operation of the exchanger is electrogenic; 4 Na+ enter and 1 K+ exits for every Ca2+ removed for a net movement of 1 positive charge inward per duty cycle. In bright light, when all of the CNG channels are closed, the exchanger continues to remove Ca2+, reducing intracellular Ca2+ by an order of magnitude. Mutations in SLC24A1 can give rise to recessive congenital stationary night blindness (Riazuddin et al. 2010).

Literature References
PubMed ID Title Journal Year
9478004 cDNA cloning of the human retinal rod Na-Ca + K exchanger: comparison with a revised bovine sequence

Tucker, JE, Schnetkamp, PP, Winkfein, RJ, Cooper, CB

Invest Ophthalmol Vis Sci 1998
20850105 A mutation in SLC24A1 implicated in autosomal-recessive congenital stationary night blindness

Hejtmancik, JF, Khan, SN, Ponferrada, VG, Husnain, T, Riazuddin, SA, Audo, I, Zeitz, C, Zafar, AU, Shahzadi, A, Ayyagari, R, Lancelot, ME, Jiao, X, Sieving, PA, MacDonald, IM, Katsanis, N, Nasir, IA, Ahmed, ZM, Michiels, C, Riazuddin, S, Chavali, VR

Am. J. Hum. Genet. 2010
Catalyst Activity

calcium, potassium:sodium antiporter activity of SLC24A1 [plasma membrane]

Inferred From
Cross References
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