ArticleThe Journal of membrane biology2009
Concentration-dependent effects on intracellular and surface pH of exposing Xenopus oocytes to solutions containing NH3/NH4(+).
Article in The Journal of membrane biology, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 27 papers.
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Who cites it
27 citing papers in PubMed, 39 citations in OpenAlex.
- Free ammonia stress rewires microbial signaling networks and constrains metabolic cooperation in oxygenic photogranules.The ISME journal · 2026Article
- Mechanism of COThe Journal of physiology · 2026Article
- Biological ammonium transporters from the Amt/Mep/Rh superfamily: mechanism, energetics, and technical limitations.Bioscience reports · 2024Review
- NHFrontiers in physiology · 2024Article
- Beyond CaPflugers Archiv : European journal of physiology · 2021Article
- Potentiometric pH Nanosensor for Intracellular Measurements: Real-Time and Continuous Assessment of Local Gradients.Analytical chemistry · 2021Article
- Imaging pH Dynamics Simultaneously in Two Cellular Compartments Using a Ratiometric pH-Sensitive Mutant of mCherry.ACS omega · 2018Article
- Mouse Slc4a11 expressed in Xenopus oocytes is an ideally selective H+/OH- conductance pathway that is stimulated by rises in intracellular and extracellular pH.American journal of physiology. Cell physiology · 2016Article
- Patch-clamp fluorometry-based channel counting to determine HCN channel conductance.The Journal of general physiology · 2016Article
- Mechanisms of ammonia and ammonium transport by rhesus-associated glycoproteins.American journal of physiology. Cell physiology · 2015Article
- Gene Deletions Resulting in Increased Nitrogen Release by Azotobacter vinelandii: Application of a Novel Nitrogen Biosensor.Applied and environmental microbiology · 2015Article
- Switching substrate specificity of AMT/MEP/ Rh proteins.Channels (Austin, Tex.) · 2014Review
- Relative CO₂/NH₃ permeabilities of human RhAG, RhBG and RhCG.The Journal of membrane biology · 2013Article
- Movement of NH₃ through the human urea transporter B: a new gas channel.American journal of physiology. Renal physiology · 2013Article
- Monitoring ion activities in and around cells using ion-selective liquid-membrane microelectrodes.Sensors (Basel, Switzerland) · 2013Review
- Loss-of-function and gain-of-function phenotypes of stomatocytosis mutant RhAG F65S.American journal of physiology. Cell physiology · 2011Article
- Adaptations to endosymbiosis in a cnidarian-dinoflagellate association: differential gene expression and specific gene duplications.PLoS genetics · 2011Article
- Periplasmic vestibule plays an important role for solute recruitment, selectivity, and gating in the Rh/Amt/MEP superfamily.Proceedings of the National Academy of Sciences of the United States of America · 2011Article
- Sharpey-Schafer lecture: gas channels.Experimental physiology · 2010Article
- pH sensitivity of ammonium transport by Rhbg.American journal of physiology. Cell physiology · 2010Article
Corrections and comments
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Authors and funding
5 authors at 2 institutions in 1 country.
Funding
Abstract
Others have shown that exposing oocytes to high levels of NH(3)/NH(4)(+) (10-20 mM) causes a paradoxical fall in intracellular pH (pH(i)), whereas low levels (e.g., 0.5 mM) cause little pH(i) change. Here we monitored pH(i) and extracellular surface pH (pH(S)) while exposing oocytes to 5 or 0.5 mM NH(3)/NH(4)(+). We confirm that 5 mM NH(3)/NH(4)(+) causes a paradoxical pH(i) fall (-DeltapH(i) approximately equal 0.2), but also observe an abrupt pH(S) fall (-DeltapH(S) approximately equal 0.2)-indicative of NH(3) influx-followed by a slow decay. Reducing [NH(3)/NH(4)(+)] to 0.5 mM minimizes pH(i) changes but maintains pH(S) changes at a reduced magnitude. Expressing AmtB (bacterial Rh homologue) exaggerates -DeltapH(S) at both NH(3)/NH(4)(+) levels. During removal of 0.5 or 5 mM NH(3)/NH(4)(+), failure of pH(S) to markedly overshoot bulk extracellular pH implies little NH(3) efflux and, thus, little free cytosolic NH(3)/NH(4)(+). A new analysis of the effects of NH(3) vs. NH(4)(+) fluxes on pH(S) and pH(i) indicates that (a) NH(3) rather than NH(4)(+) fluxes dominate pH(i) and pH(S) changes and (b) oocytes dispose of most incoming NH(3). NMR studies of oocytes exposed to (15)N-labeled NH(3)/NH(4)(+) show no significant formation of glutamine but substantial NH(3)/NH(4)(+) accumulation in what is likely an acid intracellular compartment. In conclusion, parallel measurements of pH(i) and pH(S) demonstrate that NH(3) flows across the plasma membrane and provide new insights into how a protein molecule in the plasma membrane-AmtB-enhances the flux of a gas across a biological membrane.
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