Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Am J Physiol Cell Physiol
2014 Nov 01;3079:C814-40. doi: 10.1152/ajpcell.00050.2014.
Show Gene links
Show Anatomy links
Evidence from simultaneous intracellular- and surface-pH transients that carbonic anhydrase IV enhances CO2 fluxes across Xenopus oocyte plasma membranes.
Musa-Aziz R
,
Occhipinti R
,
Boron WF
.
???displayArticle.abstract???
Human carbonic anhydrase IV (CA IV) is GPI-anchored to the outer membrane surface, catalyzing CO2/HCO3 (-) hydration-dehydration. We examined effects of heterologously expressed CA IV on intracellular-pH (pHi) and surface-pH (pHS) transients caused by exposing oocytes to CO2/HCO3 (-)/pH 7.50. CO2 influx causes a sustained pHi fall and a transient pHS rise; CO2 efflux does the opposite. Both during CO2 addition and removal, CA IV increases magnitudes of maximal rate of pHi change (dpHi/dt)max, and maximal pHS change (ΔpHS) and decreases time constants for pHi changes (τpHi ) and pHS relaxations (τpHS ). Decreases in time constants indicate that CA IV enhances CO2 fluxes. Extracellular acetazolamide blocks all CA IV effects, but not those of injected CA II. Injected acetazolamide partially reduces CA IV effects. Thus, extracellular CA is required for, and the equivalent of cytosol-accessible CA augments, the effects of CA IV. Increasing the concentration of the extracellular non-CO2/HCO3 (-) buffer (i.e., HEPES), in the presence of extracellular CA or at high [CO2], accelerates CO2 influx. Simultaneous measurements with two pHS electrodes, one on the oocyte meridian perpendicular to the axis of flow and one downstream from the direction of extracellular-solution flow, reveal that the downstream electrode has a larger (i.e., slower) τpHS , indicating [CO2] asymmetry over the oocyte surface. A reaction-diffusion mathematical model (third paper in series) accounts for the above general features, and supports the conclusion that extracellular CA, which replenishes entering CO2 or consumes exiting CO2 at the extracellular surface, enhances the gradient driving CO2 influx across the cell membrane.
Becker,
Carbonic anhydrase II increases the activity of the human electrogenic Na+/HCO3- cotransporter.
2007, Pubmed,
Xenbase
Becker,
Carbonic anhydrase II increases the activity of the human electrogenic Na+/HCO3- cotransporter.
2007,
Pubmed
,
Xenbase
Boron,
Intracellular pH transients in squid giant axons caused by CO2, NH3, and metabolic inhibitors.
1976,
Pubmed
Brown,
Localization of membrane-associated carbonic anhydrase type IV in kidney epithelial cells.
1990,
Pubmed
Busa,
Metabolic regulation via intracellular pH.
1984,
Pubmed
Chesler,
Modulation of pH by neuronal activity.
1992,
Pubmed
Chesler,
Regulation and modulation of pH in the brain.
2003,
Pubmed
Delpire,
How carbonic anhydrases and pH buffers facilitate the movement of carbon dioxide through biological membranes. Focus on "Evidence from simultaneous intracellular- and surface-pH transients that carbonic anhydrase II enhances CO2 fluxes across Xenopus oocyte plasma membranes"; "Evidence from simultaneous intracellular- and surface-pH transients that carbonic anhydrase IV enhances CO2 fluxes across Xenopus oocyte plasma membranes"; and "Evidence from mathematical modeling that carbonic anhydrase II and IV e
2014,
Pubmed
Elder,
Activation of carbonic anhydrase II by active-site incorporation of histidine analogs.
2004,
Pubmed
Fanjul,
Evidence for a membrane carbonic anhydrase IV anchored by its C-terminal peptide in normal human pancreatic ductal cells.
2004,
Pubmed
Fedirko,
Regulation of postsynaptic Ca2+ influx in hippocampal CA1 pyramidal neurons via extracellular carbonic anhydrase.
2007,
Pubmed
Fleming,
Pulmonary carbonic anhydrase IV: developmental regulation and cell-specific expression in the capillary endothelium.
1993,
Pubmed
Fleming,
Carbonic anhydrase IV expression in rat and human gastrointestinal tract regional, cellular, and subcellular localization.
1995,
Pubmed
Ghandour,
Carbonic anhydrase IV on brain capillary endothelial cells: a marker associated with the blood-brain barrier.
1992,
Pubmed
Gottfried,
Endogenous H+ modulation of NMDA receptor-mediated EPSCs revealed by carbonic anhydrase inhibition in rat hippocampus.
1994,
Pubmed
Grichtchenko,
Depolarization-induced acid secretion in gliotic hippocampal slices.
1994,
Pubmed
Gutknecht,
Diffusion of carbon dioxide through lipid bilayer membranes: effects of carbonic anhydrase, bicarbonate, and unstirred layers.
1977,
Pubmed
Gutknecht,
Diffusion of weak acids across lipid bilayer membranes: effects of chemical reactions in the unstirred layers.
1973,
Pubmed
Lu,
Effect of human carbonic anhydrase II on the activity of the human electrogenic Na/HCO3 cotransporter NBCe1-A in Xenopus oocytes.
2006,
Pubmed
,
Xenbase
Musa-Aziz,
Evidence from simultaneous intracellular- and surface-pH transients that carbonic anhydrase II enhances CO2 fluxes across Xenopus oocyte plasma membranes.
2014,
Pubmed
,
Xenbase
Nakhoul,
Effect of expressing the water channel aquaporin-1 on the CO2 permeability of Xenopus oocytes.
1998,
Pubmed
,
Xenbase
Occhipinti,
Evidence from mathematical modeling that carbonic anhydrase II and IV enhance CO2 fluxes across Xenopus oocyte plasma membranes.
2014,
Pubmed
,
Xenbase
Parkkila,
Membrane-bound carbonic anhydrase IV is expressed in the luminal plasma membrane of the human gallbladder epithelium.
1996,
Pubmed
Piermarini,
Evidence against a direct interaction between intracellular carbonic anhydrase II and pure C-terminal domains of SLC4 bicarbonate transporters.
2007,
Pubmed
Purkerson,
Expression of membrane-associated carbonic anhydrase isoforms IV, IX, XII, and XIV in the rabbit: induction of CA IV and IX during maturation.
2005,
Pubmed
Roos,
Intracellular pH.
1981,
Pubmed
Schneider,
GPI-anchored carbonic anhydrase IV displays both intra- and extracellular activity in cRNA-injected oocytes and in mouse neurons.
2013,
Pubmed
,
Xenbase
Schwartz,
Carbonic anhydrase IV is expressed in H(+)-secreting cells of rabbit kidney.
2000,
Pubmed
Sender,
Localization of carbonic anhydrase IV in rat and human heart muscle.
1998,
Pubmed
Sender,
Immunohistochemical localization of carbonic anhydrase IV in capillaries of rat and human skeletal muscle.
1994,
Pubmed
Shah,
Carbonic anhydrase IV and XIV knockout mice: roles of the respective carbonic anhydrases in buffering the extracellular space in brain.
2005,
Pubmed
Tamai,
Gly-63-->Gln substitution adjacent to His-64 in rodent carbonic anhydrase IVs largely explains their reduced activity.
1996,
Pubmed
Tanhauser,
A T7 expression vector optimized for site-directed mutagenesis using oligodeoxyribonucleotide cassettes.
1992,
Pubmed
Tong,
Interstitial carbonic anhydrase (CA) activity in brain is attributable to membrane-bound CA type IV.
2000,
Pubmed
Vullo,
Carbonic anhydrase inhibitors. Inhibition of mitochondrial isozyme V with aromatic and heterocyclic sulfonamides.
2004,
Pubmed
Whitney,
Affinity chromatography of carbonic anhydrase.
1974,
Pubmed
Zhu,
Carbonic anhydrase IV from human lung. Purification, characterization, and comparison with membrane carbonic anhydrase from human kidney.
1990,
Pubmed
