Rh glycoproteins in epithelial cells: lessons from rat and mice studies.
Rhesus glycoproteins are a recently discovered family of ammonium transporters and a new branch of the Mep/AMT proteins superfamily that was identified more than 15 years ago in lower organisms and plants. Despite many ex vivo studies showing evidences that Rh glycoproteins can accelerate transmembrane NH3 or NH4+ transfer, their role in normal and disease physiology remains unknown. This review focuses on some of the different studies carried out in animal models to gain insight into Rh glycoprotein function. Immunolocalization studies have added new evidence that this protein family is related to ammonium transport or metabolism in epithelial cells. However, the absence of distal tubular acidosis or hyperammonemia in Rhbg KO mice have raised new questions about the physiological significance of these proteins.
Inserm U652, IFR58, institut des Cordeliers, faculté de médecine René-Descartes, université Paris-Descartes, 15, rue de l'Ecole-de-Médecine, 75006 Paris, France. chambrey@ccr.jussieu.fr
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D000818:Animals; D027682:Cation Transport Proteins / Q000502:physiology*; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism; D007686:Kidney Tubules, Distal / Q000166:cytology / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D011522:Protons; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D051381:Rats
D027682:Cation Transport Proteins; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D011522:Protons; D000644:Quaternary Ammonium Compounds; C508142:Rh type B glycoprotein, rat; C508143:Rh type C glycoprotein, rat; C486033:RhBG protein, mouse; C485880:Rhcg protein, mouse