The 60- to 90-kDa parietal cell autoantigen associated with autoimmune gastritis is a beta subunit of the gastric H+/K(+)-ATPase (proton pump). Academic Article uri icon

abstract

  • Autoantibodies in the sera of patients with pernicious anemia recognize, in addition to the alpha subunit of the gastric H+/(+)-ATPase, an abundant gastric microsomal glycoprotein of apparent Mr 60,000-90,000. Herein we have colocalized the glycoprotein and the alpha subunit of the gastric H+/K(+)-ATPase to the tubulovesicular membranes of the parietal cell by immunogold electron microscopy. Moreover, the glycoprotein and the alpha subunit were coimmunoprecipitated, and copurified by immunoaffinity chromatography, with an anti-glycoprotein monoclonal antibody. The pig glycoprotein was purified by chromatography on tomato lectin-Sepharose, and five tryptic peptides from the purified glycoprotein were partially sequenced. The complete amino acid sequence, deduced from the nucleotide sequence of overlapping cDNA clones, showed 33% similarity to the sequence of the beta subunit of the pig kidney Na+/K(+)-ATPase. We therefore propose that the 60- to 90-kDa glycoprotein autoantigen is the beta subunit of the gastric H+/K(+)-ATPase and that the alpha and beta subunits of the proton pump are major targets for autoimmunization in autoimmune gastritis.

authors

  • Toh, BH
  • Gleeson, PA
  • Simpson, RJ
  • Moritz, RL
  • Callaghan, JM
  • Goldkorn, I
  • Jones, CM
  • Martinelli, TM
  • Mu, FT
  • Humphris, DC

publication date

  • August 1, 1990

has subject area