PMID- 15856280
OWN - NLM
STAT- MEDLINE
DCOM- 20050829
LR  - 20181113
IS  - 0031-6768 (Print)
IS  - 0031-6768 (Linking)
VI  - 450
IP  - 3
DP  - 2005 Jun
TI  - Expression of the human erythroid Rh glycoprotein (RhAG) enhances both NH3 and 
      NH4+ transport in HeLa cells.
PG  - 155-67
AB  - The erythroid Rh-associated glycoprotein (RhAG) is strictly required for the 
      expression of the Rh blood group antigens carried by Rh (D,CE) proteins. A 
      biological function for RhAG in ammonium transport has been suggested by its 
      ability to improve survival of an ammonium-uptake-deficient yeast. We 
      investigated the function of RhAG by studying the entry of NH3/NH4+ in HeLa cells 
      transiently expressing the green fluorescent protein (GFP)-RhAG fusion protein 
      and using a fluorescent proton probe to measure intracellular pH (pHi). Under 
      experimental conditions that reduce the intrinsic Na/H exchanger activity, 
      exposure of control cells to a 10 mM NH4Cl- containing solution induces the 
      classic pHi response profile of cells having a high permeability to NH3 (PNH3) 
      but relatively low permeability to NH4+ (PNH4). In contrast, under the same 
      conditions, the pHi profile of cells expressing RhAG clearly indicated an 
      increased PNH4, as evidenced by secondary reacidification during NH4Cl exposure 
      and a pHi undershoot below the initial resting value upon its removal. 
      Measurements of pHi during methylammonium exposure showed that RhAG expression 
      enhances the influx of both the unprotonated and ionic forms of methylammonium. 
      Using a mathematical model to adjust passive permeabilities for a fit to the pHi 
      profiles, we found that RhAG expression resulted in a threefold increase of PNH4 
      and a twofold increase of PNH3. Our results are the first evidence that the human 
      erythroid RhAG increases the transport of both NH3 and NH4+.
FAU - Benjelloun, Fatine
AU  - Benjelloun F
AD  - Universite Rene Descartes, Inserm, U467, Paris-5, Paris, 75015, France.
FAU - Bakouh, Naziha
AU  - Bakouh N
FAU - Fritsch, Janine
AU  - Fritsch J
FAU - Hulin, Philippe
AU  - Hulin P
FAU - Lipecka, Joanna
AU  - Lipecka J
FAU - Edelman, Aleksander
AU  - Edelman A
FAU - Planelles, Gabrielle
AU  - Planelles G
FAU - Thomas, S Randall
AU  - Thomas SR
FAU - Cherif-Zahar, Baya
AU  - Cherif-Zahar B
LA  - eng
PT  - Journal Article
DEP - 20050426
PL  - Germany
TA  - Pflugers Arch
JT  - Pflugers Archiv : European journal of physiology
JID - 0154720
RN  - 0 (Barium Compounds)
RN  - 0 (Blood Proteins)
RN  - 0 (Chlorides)
RN  - 0 (Membrane Glycoproteins)
RN  - 0 (Quaternary Ammonium Compounds)
RN  - 0 (RHAG protein, human)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 0 (Sodium-Hydrogen Exchangers)
RN  - 0VK51DA1T2 (barium chloride)
RN  - 5ACL011P69 (Ouabain)
RN  - 7664-41-7 (Ammonia)
SB  - IM
MH  - Ammonia/*metabolism
MH  - Barium Compounds/pharmacology
MH  - Biological Transport/physiology
MH  - Blood Proteins/*biosynthesis
MH  - Chlorides/pharmacology
MH  - HeLa Cells
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Membrane Glycoproteins/*biosynthesis
MH  - Models, Biological
MH  - Ouabain/pharmacology
MH  - Quaternary Ammonium Compounds/*metabolism
MH  - Recombinant Fusion Proteins/biosynthesis
MH  - Sodium-Hydrogen Exchangers/metabolism
EDAT- 2005/04/28 09:00
MHDA- 2005/08/30 09:00
CRDT- 2005/04/28 09:00
PHST- 2004/07/20 00:00 [received]
PHST- 2005/01/10 00:00 [accepted]
PHST- 2004/11/02 00:00 [revised]
PHST- 2005/04/28 09:00 [pubmed]
PHST- 2005/08/30 09:00 [medline]
PHST- 2005/04/28 09:00 [entrez]
AID - 10.1007/s00424-005-1381-y [doi]
PST - ppublish
SO  - Pflugers Arch. 2005 Jun;450(3):155-67. doi: 10.1007/s00424-005-1381-y. Epub 2005 
      Apr 26.