title: H(+)-translocating ATPase and Na+/H+ antiport activities in the plasma membrane of the marine alga Platymonas viridis.
abstract: Proton transport by the vanadate-sensitive ATPase in plasma membrane (PM) vesicles from the marine unicellular microalga Platymonas viridis was investigated. The ATP-dependent generation of delta pH across the membranes of PM vesicles was followed by the changes in the absorbance of the aminoacridine probe, Acridine orange. Na+ caused the decay of delta pH generated by the ATPase, the rate of the decay being dependent on the concentrations of Na+ added. The phenomenon was specific for Na+. Amiloride inhibited Na(+)-dependent delta pH decay. The experiments support the idea of a Na(+)-extruding mechanism (H(+)-translocating ATPase plus Na+/H+ antiporter) operating in the PM of marine alga Pl. viridis.
authors.affiliation: Laboratory of Salt Exchange and Salt Tolerance, Plant Physiology Institute, Russian Academy of Science, Moscow.
authors.forename: L G
authors.initials: LG
authors.lastname: Popova
authors.forename: Y V
authors.initials: YV
authors.lastname: Balnokin
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology* / Q000378:metabolism; D056890:Eukaryota / Q000201:enzymology* / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers
chemical_list: D002352:Carrier Proteins; D017923:Sodium-Hydrogen Exchangers; D000255:Adenosine Triphosphate; D012964:Sodium; D006180:Proton-Translocating ATPases