Differential expression of Na+,K+-ATPase alpha- and beta-subunit mRNAs in rat tissues and cell lines.

We have analyzed Na+,K+-ATPase (EC 3.6.1.3) alpha- and beta-subunit mRNA expression in rat tissues and cell lines derived from the rat central nervous system. Substantial differences in the tissue and developmental specificity of expression were found for the genes encoding three isoforms of the alpha subunit. Transcripts of the alpha 1-subunit gene were detected in all tissues tested, whereas alpha 2- and alpha 3-subunit mRNA species were expressed predominantly in brain. The pattern of expression of beta-subunit mRNA also was complex and tissue specific but was distinct from that of any of the alpha-subunit mRNAs. Cell lines derived from the rat central nervous system and the pheochromocytoma PC12 expressed the mRNAs for all three alpha-subunit isoforms, whereas beta-subunit mRNA was detected only in PC12 cells. The distinct expression patterns of rat Na+,K+-ATPase mRNAs suggest that different members of the ATPase family may have specialized functions.