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 Renal Physiol
2006 Feb 01;2902:F297-305. doi: 10.1152/ajprenal.00147.2005.
Show Gene links
Show Anatomy links
Characterization of ammonia transport by the kidney Rh glycoproteins RhBG and RhCG.
Mak DO
,
Dang B
,
Weiner ID
,
Foskett JK
,
Westhoff CM
.
???displayArticle.abstract???
The erythrocyte Rh-associated glycoprotein (RhAG) was recently found to mediate transport of ammonia/ammonium when expressed in Xenopus laevis oocytes and yeast Saccharomyces cerevisiae. Nonerythroid homologs, RhBG and RhCG, are expressed in the mammalian kidney connecting segment and the collecting duct, major sites of urinary ammonia secretion. This study characterizes the transport properties of murine RhBG and RhCG by ammonium analog [14C]methylamine (MA) uptake and two-electrode voltage clamping of X. laevis oocytes. Both RhBG and RhCG mediated transport of ammonia, but differed in affinity for substrate (K(m) = 2.5 and 10 mM, respectively). The rates of RhBG- and RhCG-mediated transport were sensitive to the concentration of the protonated MA species and were stimulated by extracellular alkalosis and inhibited by acidosis, suggesting a role for H+ in the transport process. Whereas expression of RhBG or RhCG caused a small increase in plasma membrane conductance, [14C]MA uptake was not affected by depolarization of oocytes with 100 mM extracellular K+ or by clamping the membrane potential between 0 and -100 mV, indicating that RhBG- and RhCG-mediated transport was independent of the membrane potential. These results strongly suggest that RhBG and RhCG transport ammonia by an electroneutral process that involves NH4(+)/H+ exchange resulting in net NH3 translocation. The polarized localization of RhBG and RhCG in kidney tubules and the different substrate affinities may enable these proteins to participate in transepithelial ammonia secretion and to therefore play an important role in whole animal acid-base regulation.
Bakouh,
NH3 is involved in the NH4+ transport induced by the functional expression of the human Rh C glycoprotein.
2004, Pubmed,
Xenbase
Bakouh,
NH3 is involved in the NH4+ transport induced by the functional expression of the human Rh C glycoprotein.
2004,
Pubmed
,
Xenbase
Boldt,
NH(4)(+) conductance in Xenopus laevis oocytes. III. Effect of NH(3).
2003,
Pubmed
,
Xenbase
Bröer,
Chloride conductance and Pi transport are separate functions induced by the expression of NaPi-1 in Xenopus oocytes.
1998,
Pubmed
,
Xenbase
Burckhardt,
Pathways of NH3/NH4+ permeation across Xenopus laevis oocyte cell membrane.
1992,
Pubmed
,
Xenbase
Buyse,
Expression of human pICln and ClC-6 in Xenopus oocytes induces an identical endogenous chloride conductance.
1997,
Pubmed
,
Xenbase
DuBose,
Ammonium transport in the kidney: new physiological concepts and their clinical implications.
1991,
Pubmed
DuBose,
Micropuncture determination of pH, PCO2, and total CO2 concentration in accessible structures of the rat renal cortex.
1979,
Pubmed
Filho,
H in cortical peritubular capillaries of rat kidney.
1976,
Pubmed
Flessner,
Ammonium and bicarbonate transport in rat outer medullary collecting ducts.
1992,
Pubmed
Frank,
Mechanisms through which ammonia regulates cortical collecting duct net proton secretion.
2002,
Pubmed
Good,
Transepithelial ammonia concentration gradients in inner medulla of the rat.
1987,
Pubmed
Hamm,
Transport of ammonia in the rabbit cortical collecting tubule.
1985,
Pubmed
Handlogten,
Apical ammonia transport by the mouse inner medullary collecting duct cell (mIMCD-3).
2005,
Pubmed
Handlogten,
Basolateral ammonium transport by the mouse inner medullary collecting duct cell (mIMCD-3).
2004,
Pubmed
Handlogten,
Expression of the ammonia transporter proteins Rh B glycoprotein and Rh C glycoprotein in the intestinal tract.
2005,
Pubmed
Jiang,
Cystic fibrosis transmembrane conductance regulator-associated ATP release is controlled by a chloride sensor.
1998,
Pubmed
,
Xenbase
Khademi,
Mechanism of ammonia transport by Amt/MEP/Rh: structure of AmtB at 1.35 A.
2004,
Pubmed
Kinne,
Ammonium transport in medullary thick ascending limb of rabbit kidney: involvement of the Na+,K+,Cl(-)-cotransporter.
1986,
Pubmed
Kinsella,
Interaction of NH4+ and Li+ with the renal microvillus membrane Na+-H+ exchanger.
1981,
Pubmed
Kleiner,
The transport of NH3 and NH4+ across biological membranes.
1981,
Pubmed
Knepper,
Ammonium transport in the kidney.
1989,
Pubmed
Liu,
Characterization of human RhCG and mouse Rhcg as novel nonerythroid Rh glycoprotein homologues predominantly expressed in kidney and testis.
2000,
Pubmed
Liu,
Rh type B glycoprotein is a new member of the Rh superfamily and a putative ammonia transporter in mammals.
2001,
Pubmed
Ludewig,
Electroneutral ammonium transport by basolateral rhesus B glycoprotein.
2004,
Pubmed
,
Xenbase
Ludewig,
Uniport of NH4+ by the root hair plasma membrane ammonium transporter LeAMT1;1.
2002,
Pubmed
,
Xenbase
Marini,
Cloning and expression of the MEP1 gene encoding an ammonium transporter in Saccharomyces cerevisiae.
1994,
Pubmed
Marini,
A family of ammonium transporters in Saccharomyces cerevisiae.
1997,
Pubmed
Marini,
The human Rhesus-associated RhAG protein and a kidney homologue promote ammonium transport in yeast.
2000,
Pubmed
Meier-Wagner,
Multiplicity of ammonium uptake systems in Corynebacterium glutamicum: role of Amt and AmtB.
2001,
Pubmed
Nakhoul,
Characteristics of renal Rhbg as an NH4(+) transporter.
2005,
Pubmed
,
Xenbase
Nessler,
Evidence for activation of endogenous transporters in Xenopus laevis oocytes expressing the Plasmodium falciparum chloroquine resistance transporter, PfCRT.
2004,
Pubmed
,
Xenbase
Ninnemann,
Identification of a high affinity NH4+ transporter from plants.
1994,
Pubmed
Quentin,
RhBG and RhCG, the putative ammonia transporters, are expressed in the same cells in the distal nephron.
2003,
Pubmed
Roon,
Methylamine and ammonia transport in Saccharomyces cerevisiae.
1975,
Pubmed
Sha,
Heterologous expression of the Na(+),K(+)-ATPase gamma subunit in Xenopus oocytes induces an endogenous, voltage-gated large diameter pore.
2001,
Pubmed
,
Xenbase
Shimbo,
Viral and cellular small integral membrane proteins can modify ion channels endogenous to Xenopus oocytes.
1995,
Pubmed
,
Xenbase
Verlander,
Localization of the ammonium transporter proteins RhBG and RhCG in mouse kidney.
2003,
Pubmed
Wall,
Ammonium transport and the role of the Na,K-ATPase.
1996,
Pubmed
Weiner,
Localization of the ammonium transporters, Rh B glycoprotein and Rh C glycoprotein, in the mouse liver.
2003,
Pubmed
Westhoff,
Identification of the erythrocyte Rh blood group glycoprotein as a mammalian ammonium transporter.
2002,
Pubmed
,
Xenbase
Westhoff,
Mechanism of genetic complementation of ammonium transport in yeast by human erythrocyte Rh-associated glycoprotein.
2004,
Pubmed
,
Xenbase
Zheng,
The mechanism of ammonia transport based on the crystal structure of AmtB of Escherichia coli.
2004,
Pubmed
