Subunit assembly and posttranslational processing of Na(+)-pumps.
Assembly, posttranslational processing and intracellular transport of Na,K-ATPase subunits are closely linked processes. Only coexpression of alpha- and beta-subunits in Xenopus oocytes permits the structural maturation and the ER exit of the two subunits. A putative beta 3-isoform of Na,K-ATPase and the beta-subunit of H,K-ATPase can support similar functions to those of beta 1-subunits of Na,K-ATPase in allowing the functional expression of alpha-beta complexes with Na,K-pump transport properties in the plasma membrane. These data indicate that a primary role of the beta subunit is to impose a conformational change on the newly synthesized alpha-subunits probably involved in the acquisition of transport competence and functional maturity of the catalytic alpha-subunit.
Geering
K
K
Institute de Pharmacologie et de Toxicologie, l'Université de Lausanne, Switzerland.
D000818:Animals; D007527:Isoenzymes / Q000378:metabolism; D009865:Oocytes / Q000201:enzymology; D010042:Ouabain / Q000378:metabolism; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D000254:Sodium-Potassium-Exchanging ATPase / Q000096:biosynthesis* / Q000502:physiology*; D014981:Xenopus
D007527:Isoenzymes; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase