title: Rat-brain Na,K-ATPase beta-chain gene: primary structure, tissue-specific expression, and amplification in ouabain-resistant HeLa C+ cells.
abstract: We deduced the complete amino acid sequence of the rat brain Na,K-ATPase beta-subunit from cDNA. The rat brain beta-subunit exhibits a high degree of primary sequence and secondary structural homology with the human and Torpedo beta-subunit polypeptides. Analysis of rat tissue RNA reveals that the beta-subunit gene encodes four separate mRNA species which are expressed in a tissue-specific fashion. In ouabain-resistant HeLa C+ cells, beta-subunit DNA sequences are amplified (approximately 20-fold) and beta-subunit mRNAs are overproduced relative to levels in parental HeLa cells. These results suggest that the beta-subunit plays an important role in Na,K-ATPase structure-function and in the mechanism underlying cellular resistance to the cardiac glycosides.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000201:enzymology*; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004351:Drug Resistance; D005784:Gene Amplification; D005796:Genes; D006367:HeLa Cells / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D046911:Macromolecular Substances; D010042:Ouabain / Q000494:pharmacology*; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D013045:Species Specificity; D014101:Torpedo
chemical_list: D046911:Macromolecular Substances; D010042:Ouabain; D004247:DNA; D000254:Sodium-Potassium-Exchanging ATPase