Identification of three isozyme proteins of the catalytic subunit of the Na,K-ATPase in rat brain.

摘要: Abstract Molecular genetic evidence indicates that there should be three different (Na+ + K+)-stimulated ATPase (Na,K-ATPase) alpha subunit isozymes in the brain where previously only two ("alpha" and "alpha(+)") were resolved as proteins. To detect identify 1, 2, 3 isozymes, polypeptides made by cell-free translation (Schneider, J.W., Mercer, R.W., Gilmore-Hebert, M., Utset, M.F., Lai, C., Greene, A., Benz, E.J., Jr. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 284-288) analyzed gel electrophoresis proteolytic fingerprinting. Synthetic 1 comigrated with tissue while 2 leading trailing edges, respectively, of "alpha(+)." Proteolytic fingerprints newborn rat Na,K-ATPase labeled vivo L-[35S]methionine indicated presence 3, a low level 2. Monoclonal antibodies characterized electrophoretic mobility their antigens ability to recognize Na,K-ATPases kidney, brain, skeletal muscle. The used assess isozyme expression brain. All increased abundance during development from 18-day fetus adult. Small changes seen relative at developmental ages, markedly between neonate In adult all found regions examined. We conclude are expressed proteins distribution must under complex control. No single age or macroscopic region provides an exclusive source any isozymes.