The Na+, K+-Transporting Adenosine Triphosphatase

Glynn, I. M.

doi:10.1007/978-1-4684-4601-2_2

Cited by 241 publications

(232 citation statements)

References 416 publications

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“…4G and 6). Ouabain binds to the Na ϩ ͞K ϩ -ATPase in the E 2 P conformation (35,36), in agreement with the observed low fluorescence level (indicative of E 2 P). Transient currents in the Na ϩ ͞Na ϩ exchange mode are often defined as ouabain-sensitive currents in the literature (19,(21)(22)(23).…”

Section: Voltage-dependent Charge Movement and Fluorescence Changesupporting

confidence: 78%

Conformational dynamics of the Na ⁺ /K ⁺ -ATPase probed by voltage clamp fluorometry

Geibel

Kaplan

Bamberg

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

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The method of voltage clamp fluorometry combined with sitedirected fluorescence labeling was used to detect local protein motions of the fully active Na ؉ ͞K ؉ -ATPase in real time under physiological conditions. Because helix M5 extends from the cytoplasmic site of ATP hydrolysis into the cation binding region, we chose the extracellular M5-M6 loop of the sheep ␣1-subunit for the insertion of cysteine residues to identify reporter positions for conformational rearrangements during the catalytic cycle. After expression of the single cysteine mutants in Xenopus oocytes and covalent attachment of tetramethylrhodamine-6-maleimide, only mutant N790C reported molecular rearrangements of the M5-M6 loop by showing large, ouabain-sensitive fluorescence changes (Ϸ5%) on addition of extracellular K ؉ . When the enzyme was subjected to voltage jumps under Na ؉ ͞Na ؉ -exchange conditions, we observed fluorescence changes that directly correlated to transient charge movements originating from the E1P-E2P transition of the transport cycle. The voltage jump-induced fluorescence changes and transient currents were abolished after replacement of Na ؉ by tetraethylammonium or on addition of ouabain, showing that conformational flexibility is impaired under these conditions. Voltage-dependent fluorescence changes could also be observed in the presence of subsaturating K ؉ concentrations. This allowed to monitor the time course of voltage-dependent relaxations into a new stationary distribution of states under turnover conditions, showing the acceleration of relaxation kinetics with increasing K ؉ concentrations. As a result, the stationary distribution between E1 and E2 states and voltage-dependent relaxation times can be determined at any time and membrane potential under Na ؉ ͞Na ؉ exchange as well as Na ؉ ͞K ؉ turnover conditions. P -type ATPases form a major class of primary active membrane transport proteins, so called because they become transiently phosphorylated on ATP hydrolysis. The most prominent member is the ubiquitously occurring Na ϩ ͞K ϩ -ATPase, which exports three Na ϩ ions and imports two K ϩ ions in each transport cycle and thereby maintains the electrochemical gradients of Na ϩ and K ϩ across the plasma membrane of most animal cells.The reaction cycle of the Na ϩ ͞K ϩ -ATPase is described in terms of the Albers-Post scheme (see Fig. 1A) (1, 2). The transduction of primary energy from ATP hydrolysis to active ion transport is brought about by conformational changes that occur for both the ␣ and ␤ subunit of the Na ϩ ͞K ϩ -ATPase (3-6). Several approaches were undertaken to reveal Na ϩ ͞K ϩ -ATPase conformational changes by using fluorescence labeling of the native enzyme with fluorescein-5Ј-isothiocyanate, N-(p-(2-benzimidazolyl)phenyl)-maleimide and styrylpyridinium dyes like RH421 (7-12), which were limited for several reasons. Purely biochemical assays to investigate conformationdependent proteolysis patterns cannot provide time-resolved data, in the case of fluorescence labeling with styryl dyes the site of...

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Section: Voltage-dependent Charge Movement and Fluorescence Changesupporting

confidence: 78%

Conformational dynamics of the Na ⁺ /K ⁺ -ATPase probed by voltage clamp fluorometry

Geibel

Kaplan

Bamberg

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

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“…This gradient energizes the Na+/Ca 2+ exchange which plays an important function in excitable cells (Baker, 1972). Furthermore, the role of the Na+/K + pump in the regulation of membrane potential and cell volume is well known (Glynn, 1985). Therefore virus-mediated alterations of the Ca 2÷ and Na+/K ÷ pumps may result in cation imbalances that, according to their importance and the type of cell involved, may lead to structural damage of the cell and/or may induce perturbations of cellular functions, among which the specialized functions of secretory and excitable cells should be particularly sensitive (Cheung, 1983(Cheung, , 1984.…”

Section: Discussionmentioning

confidence: 99%

Tacaribe Virus Infection May Induce Inhibition of the Activity of the Host Cell Ca2+ and Na+/K+ Pumps

Rey

Rossi²,

López³

et al. 1988

Journal of General Virology

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SUMMARYInfection of Vero cells with Tacaribe virus stocks containing a high ratio of standard (plaque-forming) viruses to defective interfering particles (DIP) induced inhibition of the host cell Ca 2+ ATPase (Ca 2+ pump) and the ouabain-sensitive Na+/K + ATPase (Na+/K + pump). The Mg 2+ ATPase which is not involved in cation transport was not affected. The presence of DIP in the inocula protected the cells from alteration of the transport-associated ATPases induced by standard viruses.

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“…across cell membranes using the energy provided by ATP hydrolysis (1)(2)(3)(4). The study of key members of this family, like the Na,K-ATPase and the sarcoplasmic reticulum (SR) 1 Ca-ATPase, has allowed the description of significant aspects of their catalytic cycle (2,3).…”

Section: P-type Atpases Transport a Variety Of Ions (Hmentioning

confidence: 99%

Characterization of a Thermophilic P-type Ag+/Cu+-ATPase from the ExtremophileArchaeoglobus fulgidus

Mandal

Cheung²,

Argüello

2002

Journal of Biological Chemistry

123

192

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The thermophilic, sulfur metabolizing Archaeoglobus fulgidus contains two genes, AF0473 and AF0152, encoding for PIB-type heavy metal transport ATPases. In this study, we describe the cloning, heterologous expression, purification, and functional characterization of one of these ATPases, CopA (NCB accession number AAB90763), encoded by AF0473. 50 ‫؍‬ 24 M). This is the first Ag ؉ /Cu ؉ -ATPase expressed and purified in a functional form. Thus, it provides a model for structurefunctional studies of these transporters. Moreover, its characterization will also contribute to an understanding of thermophilic ion transporters.

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The Na+, K+-Transporting Adenosine Triphosphatase

Cited by 241 publications

References 416 publications

Conformational dynamics of the Na ⁺ /K ⁺ -ATPase probed by voltage clamp fluorometry

Conformational dynamics of the Na ⁺ /K ⁺ -ATPase probed by voltage clamp fluorometry

Tacaribe Virus Infection May Induce Inhibition of the Activity of the Host Cell Ca2+ and Na+/K+ Pumps

Characterization of a Thermophilic P-type Ag+/Cu+-ATPase from the ExtremophileArchaeoglobus fulgidus

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The Na+, K+-Transporting Adenosine Triphosphatase

Cited by 241 publications

References 416 publications

Conformational dynamics of the Na + /K + -ATPase probed by voltage clamp fluorometry

Conformational dynamics of the Na + /K + -ATPase probed by voltage clamp fluorometry

Tacaribe Virus Infection May Induce Inhibition of the Activity of the Host Cell Ca2+ and Na+/K+ Pumps

Characterization of a Thermophilic P-type Ag+/Cu+-ATPase from the ExtremophileArchaeoglobus fulgidus

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Conformational dynamics of the Na ⁺ /K ⁺ -ATPase probed by voltage clamp fluorometry

Conformational dynamics of the Na ⁺ /K ⁺ -ATPase probed by voltage clamp fluorometry