|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pflanzenphysiologie, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, Germany
The liver and kidney are important tissues for ammonium (NH4+/NH3) metabolism and excretion. The rhesus B glycoprotein (RhBG) is a membrane protein expressed in liver and kidney with similarity to NH4+ transporters found in microorganisms, plants and animals. In the kidney, RhBG is predominantly localized to basolateral membranes of distal tubule epithelia, including connecting tubules and collecting ducts. These epithelia display mainly electroneutral ammonium transport, in contrast to other tubular sites, where net NH4+ transport occurs. In accordance with its localization, human RhBG mediates saturable, electroneutral transport of the ammonium analogue methylammonium when heterologously expressed in Xenopus oocytes. Uptake of methylammonium saturates with a Km= 2.6 mM. Methylammonium uptake is inhibited by ammonium and this inhibition saturates with a Ki
3 mM. Electric current measurements and intracellular pHi determinations suggest that RhBG acts as an electroneutral NH4+H+ exchanger.
(Received 5 May 2004;
accepted after revision 26 July 2004;
first published online 29 July 2004)
Corresponding author U. Ludewig: Pflanzenphysiologie, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, Germany. Email: uwe.ludewig{at}zmbp.uni-tuebingen.de
This article has been cited by other articles:
![]() |
R. T. Worrell, L. Merk, and J. B. Matthews Ammonium transport in the colonic crypt cell line, T84: role for Rhesus glycoproteins and NKCC1 Am J Physiol Gastrointest Liver Physiol, February 1, 2008; 294(2): G429 - G440. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Lupo, X.-D. Li, A. Durand, T. Tomizaki, B. Cherif-Zahar, G. Matassi, M. Merrick, and F. K. Winkler The 1.3-A resolution structure of Nitrosomonas europaea Rh50 and mechanistic implications for NH3 transport by Rhesus family proteins PNAS, December 4, 2007; 104(49): 19303 - 19308. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Li, S. Jayachandran, H.-H. T. Nguyen, and M. K. Chan Structure of the Nitrosomonas europaea Rh protein PNAS, December 4, 2007; 104(49): 19279 - 19284. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Nakada, K. Hoshijima, M. Esaki, S. Nagayoshi, K. Kawakami, and S. Hirose Localization of ammonia transporter Rhcg1 in mitochondrion-rich cells of yolk sac, gill, and kidney of zebrafish and its ionic strength-dependent expression Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2007; 293(4): R1743 - R1753. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Nakada, C. M. Westhoff, A. Kato, and S. Hirose Ammonia secretion from fish gill depends on a set of Rh glycoproteins FASEB J, April 1, 2007; 21(4): 1067 - 1074. [Abstract] [Full Text] [PDF] |
||||
![]() |
K.-H. Han, B. P. Croker, W. L. Clapp, D. Werner, M. Sahni, J. Kim, H.-Y. Kim, M. E. Handlogten, and I. D. Weiner Expression of the Ammonia Transporter, Rh C Glycoprotein, in Normal and Neoplastic Human Kidney J. Am. Soc. Nephrol., October 1, 2006; 17(10): 2670 - 2679. [Abstract] [Full Text] [PDF] |
||||
![]() |
D.-O. D. Mak, B. Dang, I. D. Weiner, J. K. Foskett, and C. M. Westhoff Characterization of ammonia transport by the kidney Rh glycoproteins RhBG and RhCG Am J Physiol Renal Physiol, February 1, 2006; 290(2): F297 - F305. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. M. Seshadri, J. D. Klein, S. Kozlowski, J. M. Sands, Y.-H. Kim, K.-H. Han, M. E. Handlogten, J. W. Verlander, and I. D. Weiner Renal expression of the ammonia transporters, Rhbg and Rhcg, in response to chronic metabolic acidosis Am J Physiol Renal Physiol, February 1, 2006; 290(2): F397 - F408. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Mayer, G. Schaaf, I. Mouro, C. Lopez, Y. Colin, P. Neumann, J.-P. Cartron, and U. Ludewig Different Transport Mechanisms in Plant and Human AMT/Rh-type Ammonium Transporters J. Gen. Physiol., January 30, 2006; 127(2): 133 - 144. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Chambrey, D. Goossens, S. Bourgeois, N. Picard, M. Bloch-Faure, F. Leviel, V. Geoffroy, M. Cambillau, Y. Colin, M. Paillard, et al. Genetic ablation of Rhbg in the mouse does not impair renal ammonium excretion Am J Physiol Renal Physiol, December 1, 2005; 289(6): F1281 - F1290. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Obermeyer and S. D. Tyerman NH4+ Currents across the Peribacteroid Membrane of Soybean. Macroscopic and Microscopic Properties, Inhibition by Mg2+, and Temperature Dependence Indicate a SubpicoSiemens Channel Finely Regulated by Divalent Cations Plant Physiology, October 1, 2005; 139(2): 1015 - 1029. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Handlogten, S.-P. Hong, L. Zhang, A. W. Vander, M. L. Steinbaum, M. Campbell-Thompson, and I. D. Weiner Expression of the ammonia transporter proteins Rh B glycoprotein and Rh C glycoprotein in the intestinal tract Am J Physiol Gastrointest Liver Physiol, May 1, 2005; 288(5): G1036 - G1047. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Lopez, S. Metral, D. Eladari, S. Drevensek, P. Gane, R. Chambrey, V. Bennett, J.-P. Cartron, C. Le Van Kim, and Y. Colin The Ammonium Transporter RhBG: REQUIREMENT OF A TYROSINE-BASED SIGNAL AND ANKYRIN-G FOR BASOLATERAL TARGETING AND MEMBRANE ANCHORAGE IN POLARIZED KIDNEY EPITHELIAL CELLS J. Biol. Chem., March 4, 2005; 280(9): 8221 - 8228. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |