Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-38490
Wagner, C A; Devuyst, O; Belge, H; Bourgeois, S; Houillier, P (2011). The rhesus protein RhCG: a new perspective in ammonium transport and distal urinary acidification. Kidney International, 79(2):154-161.
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Urinary acidification is a complex process requiring the coordinated action of enzymes and transport proteins and resulting in the removal of acid and the regeneration of bicarbonate. Proton secretion is mediated by luminal H(+)-ATPases and requires the parallel movement of NH(3), and its protonation to NH(4)(+), to provide sufficient buffering. It has been long assumed that ammonia secretion is a passive process occurring by means of simple diffusion driven by the urinary trapping of ammonium. However, new data indicate that mammalian cells possess specific membrane proteins from the family of rhesus proteins involved in ammonia/μm permeability. Rhesus proteins were first identified in yeast and later also in plants, algae, and mammals. In rodents, RhBG and RhCG are expressed in the collecting duct, whereas in humans only RhCG was detected. Their expression increases with maturation of the kidney and accelerates after birth in parallel with other acid-base transport proteins. Deletion of RhBG in mice had no effect on renal ammonium excretion, whereas RhCG deficiency reduces renal ammonium secretion strongly, causes metabolic acidosis in acid-challenged mice, and impairs restoration of normal acid-base status. Microperfusion experiments or functional reconstitution in liposomes demonstrates that ammonia is the most likely substrate of RhCG. Similarly, crystal structures of human RhCG and the homologous bacterial AmtB protein suggest that these proteins may form gas channels.Kidney International advance online publication, 6 October 2010; doi:10.1038/ki.2010.386.
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|Item Type:||Journal Article, refereed, further contribution|
|Communities & Collections:||04 Faculty of Medicine > Institute of Physiology
07 Faculty of Science > Institute of Physiology
|DDC:||570 Life sciences; biology|
|Deposited On:||17 Jan 2011 14:11|
|Last Modified:||27 Nov 2013 20:55|
|Publisher:||Nature Publishing Group|
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