title: The ATP-driven Na(+)-pump in the plasma membrane of the marine unicellular alga, Platymonas viridis.
abstract: The ATP-supported 22NA+ uptake by plasma membrane vesicles from the marine microalga, Platymonas viridis, was studied. At pH 7 in the medium, Na+ uptake did not occur in the presence of ATP although delta pH across the plasma membrane was generated. The ATP-dependent Na+ uptake was induced by adding the protonophore, ClCCP. At pH 8, Na+ uptake took place when ATP was added even without ClCCP. The delta pH generated across the plasma membrane was negligible under these conditions. The Na+ uptake at pH 8 was not affected by ClCCP and amiloride, an inhibitor of the Na+/H+ antiporter. It is concluded that the ATP-supported Na+ uptake by Pl. viridis vesicles is catalyzed by Na(+)-ATPase.
authors.affiliation: Laboratory of Salt Exchange and Salt Tolerance, Russian Academy of Science, Moscow.
authors.forename: Y V
authors.initials: YV
authors.lastname: Balnokin
authors.forename: L G
authors.initials: LG
authors.lastname: Popova
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D002462:Cell Membrane / Q000378:metabolism; D000460:Chlorophyta / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
chemical_list: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000255:Adenosine Triphosphate; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase