Molecular characterization and expression of the (Na+ + K+)-ATPase alpha-subunit in Drosophila melanogaster

EMBO J. 1989 Jan;8(1):193-202.

Abstract

The (Na+ + K+)-ATPase (sodium pump) is an ouabain-sensitive, electrogenic ion pump responsible for maintaining the balance of sodium and potassium ions in almost all animal cells. Robust, ouabain-sensitive rubidium uptake, indicative of the sodium pump, was found in tissue-cultured Drosophila cells, and both larvae and adults die when fed a diet containing ouabain. A monoclonal antibody to the avian sodium pump alpha-subunit was found to cross-react with the Drosophila sodium pump alpha-subunit. Immunofluorescence microscopy was used to obtain a semi-quantitative view of the expression of the sodium pump in Drosophila tissues: high levels of the sodium pump were detected in malpighian tubules, indirect flight muscles and tubular muscles, and throughout the nervous system. The cDNA encoding this sodium pump alpha-subunit in Drosophila melanogaster was cloned, sequenced and expressed in mouse L cells. At the amino acid level, its deduced sequence of 1038 residues (the first such sequence for an invertebrate) is approximately 80% similar to alpha-subunit sequences reported for vertebrates. Only one gene was found in Drosophila, located on the third chromosome at position 93B. A restriction site polymorphism has been found, and several mutations exist that may involve the alpha-subunit gene.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cells, Cultured
  • Chromosome Mapping
  • DNA / genetics
  • Drosophila melanogaster / enzymology*
  • Drosophila melanogaster / genetics
  • L Cells
  • Mice
  • Molecular Sequence Data
  • Ouabain / pharmacology
  • RNA, Messenger / analysis
  • Recombinant Fusion Proteins / biosynthesis
  • Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors
  • Sodium-Potassium-Exchanging ATPase / biosynthesis
  • Sodium-Potassium-Exchanging ATPase / genetics*

Substances

  • RNA, Messenger
  • Recombinant Fusion Proteins
  • Ouabain
  • DNA
  • Sodium-Potassium-Exchanging ATPase

Associated data

  • GENBANK/X14476