The Na+/K+-transporting ATPase trimer exchanges sodium for potassium Authored: Jassal, B, 2010-08-24 EC Number: 3.6.3.9 Edited: Jassal, B, 2010-08-24 Pubmed11062458 Pubmed12119109 Pubmed12953268 Pubmed15174025 Pubmed15260953 Pubmed2430951 Pubmed2477373 Pubmed2559024 Pubmed2838329 Pubmed8798450 Pubmed8918259 Pubmed9048881 Reactome Database ID Release 43936897 Reactome, http://www.reactome.org ReactomeREACT_25287 Reviewed: He, L, 2010-11-15 The sodium/potassium-transporting ATPase is composed of three subunits - alpha (catalytic part), beta and gamma. The trimer catalyzes the hydrolysis of ATP coupled with the exchange of sodium and potassium ions across the plasma membrane, creating the electrochemical gradient which provides energy for the active transport of various nutrients.<br>Four human genes encode the catalytic alpha subunits, ATP1A1-4 (Kawakami et al, 1986; Shull et al, 1989; Ovchinnikov et al, 1988; Keryanov and Gardner, 2002). Defects in ATP1A2 cause alternating hemiplegia of childhood (AHC) (Swoboda et al, 2004). Another defect in ATP1A2 causes familial hemiplegic migraine type 2 (FHM2) (Vanmolkot et al, 2003). Defects in ATP1A3 are the cause of dystonia type 12 (DYT12) (de Carvalho Aguiar et al, 2004).<br><br>Three human genes encode the non-catalytic beta subunits, ATP1B1-3. The beta subunits are thought to mediate the number of sodium pumps transported to the plasma membrane (Lane et al, 1989; Ruiz et al, 1996; Malik et al, 1996). The human gene FXYD2 encodes the non-catalytic gamma subunit of Na+/K+ ATPase (Kim et al, 1997). Defects in FXYD2 are the cause of hypomagnesemia type 2 (HOMG2) (Meij et al, 2000).