title: Expression of Na(+)-K(+)-ATPase alpha 1- and alpha 3-isoforms in adult and neonatal ferret hearts.
abstract: We have demonstrated previously that in adult ferret heart two alpha-subunit isoforms of the Na(+)-K(+)-ATPase, alpha(+) and alpha, are expressed. The alpha(+)-isoform may comprise either alpha 2-, or alpha 3-, or both isoforms. The present studies further characterize the alpha(+)-isoform. The alpha(+)-isoform of ferret heart did not react with an alpha 2-specific monoclonal antibody, but rather with two different alpha 3-specific polyclonal antibodies. Electrophoretic mobility of the alpha(+)-isoform in sodium dodecyl sulfate polyacrylamide gel electrophoresis is slower than that of the alpha 2-isoform, but similar to that of the alpha 3-isoform. Limited proteolytic peptide mapping was performed using Staphylococcus aureus V8. Proteolytic fragments were then immunostained with an alpha 3-specific antibody. The peptide maps of ferret heart alpha(+)-isoform and rat brain alpha 3-isoform were identical, as were those of ferret heart alpha(+)-isoform and ferret brain alpha 3-isoform. These results indicate that the alpha(+)-isoform of ferret heart is an alpha 3-isoform. During postnatal development, the same isoforms expressed in the adult ferret heart (alpha 1 and alpha 3), were also expressed in neonatal heart. In adult or neonatal heart alpha 2-isoform was not detectable. Relative abundances of the isoforms in ventricular and atrial tissues differed. Compared with ventricular tissue, left and right atrial tissues expressed much less alpha 3 than alpha 1. It is concluded that, unlike rat heart, alpha 1- and alpha 3-isoforms are expressed in adult ferret heart.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Pharmacology, Milton S. Hershey Medical Center, College of Medicine, Pennsylvania State University, Hershey 17033.
authors.forename: Y C
authors.initials: YC
authors.lastname: Ng
authors.forename: C B
authors.initials: CB
authors.lastname: Book
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D000906:Antibodies / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005289:Ferrets; D006321:Heart / Q000254:growth & development; D006325:Heart Atria; D015151:Immunoblotting; D007527:Isoenzymes / Q000276:immunology / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010449:Peptide Mapping; D000254:Sodium-Potassium-Exchanging ATPase / Q000276:immunology / Q000378:metabolism*
chemical_list: D000906:Antibodies; D007527:Isoenzymes; D000254:Sodium-Potassium-Exchanging ATPase