In vitro expression of the alpha and beta subunits of the Na,K-ATPase.

Our analysis of the cloned alpha 3 protein strongly suggests that this c-DNA represents a bona fide Na+,K+ ATPase isoform. Its similarity to alpha + may have made its detection in tissues by gel migration or immunoreactivity difficult. Expression of an enzymatically active alpha 3 beta Na+K+ATPase either in a completely in vitro system or in a heterologous tissue culture system will clearly establish the biochemical properties of this isoform. Development of alpha 3 specific immunochemical probes will allow a proper assessment of its in vivo expression.