Molecular cloning of rat brain Na,K-ATPase alpha-subunit cDNA.

作者：Jay W. Schneider, R W Mercer, Michael J. Caplan, Janet Rettig Emanuel, Kathleen J. Sweadner, E J Benz, Robert G. Levenson · 发表于：Proceedings of the National Academy of Sciences · 年份：1985 · DOI：10.1073/pnas.82.18.6357 · 被引用次数：77 · 研究领域：Ion Transport and Channel Regulation、Amino Acid Enzymes and Metabolism、Drug Transport and Resistance Mechanisms

We have isolated a cDNA clone for the rat brain Na,K-ATPase alpha subunit. A lambda gt11 cDNA expression library constructed from mRNA of 1- and 2-week-old rat brains was screened with an antibody reactive with rat brain Na,K-ATPase. A positive phage clone, lambda rb5, containing a 1200-base-pair cDNA insert expressed a beta-galactosidase-cDNA fusion protein that was reactive by immunoblotting with the Na,K-ATPase antibody. This fusion protein was also reactive in ELISA with a monoclonal antibody directed against the alpha subunit of the Na,K-ATPase. A 27S mRNA species exhibiting sequence hybridization to the cDNA insert of lambda rb5 was identified in rat brain, kidney, and liver, as well as in dog kidney. This 27S mRNA exhibited a tissue-specific pattern of abundance consistent with the relative abundance of Na,K-ATPase polypeptides in vivo: kidney greater than brain greater than liver. In a ouabain-resistant HeLa cell line, C+, which contains minute chromosomes and at least a 10-fold greater number of sodium pumps than parental HeLa cells, DNA sequences complementary to lambda rb5 cDNA were amplified approximately 40-fold. Analysis of the lambda rb5 cDNA sequence demonstrated a perfect nucleotide sequence match between a portion of the cDNA and the amino acid sequence of the Na,K-ATPase alpha-subunit fluorescein isothiocyanate binding site. Taken together, the data presented here demonstrate that the lambda rb5 cDNA clone is a portion of the gene coding for the rat brain N...