Rhesus is commonly defined as a ‘factor’ that determines, in part, blood type, and whether neonates suffer from haemolytic disease of the newborn. These glycoprotein antigens derive from two genes, RHCE (P18577) and RHD (Q02161), expressed on the surface of erythrocytes. On erythrocytes, RhAG associates with these antigens and functions as an ammonium transporter. RhBG and RhBG are non-erythroid related sequences associated with epithelia. Topological modelling suggests the presence of 12TM with cytoplasmic N- and C- termini. The majority of information on these transporters derives from orthologues in yeast, plants and bacteria. More recent evidence points to family members being permeable to carbon dioxide, leading to the term gas channels.

* Key recommended reading is highlighted with an asterisk

Huang CH, Ye M. (2010) The Rh protein family: gene evolution, membrane biology, and disease association. Cell Mol Life Sci, 67 (8): 1203-18. [PMID:19953292]

Nakhoul NL, Hamm LL. (2004) Non-erythroid Rh glycoproteins: a putative new family of mammalian ammonium transporters. Pflugers Arch, 447 (5): 807-12. [PMID:12920597]

* Nakhoul NL, Lee Hamm L. (2013) Characteristics of mammalian Rh glycoproteins (SLC42 transporters) and their role in acid-base transport. Mol Aspects Med, 34 (2-3): 629-37. [PMID:23506896]

* Weiner ID, Verlander JW. (2011) Role of NH3 and NH4+ transporters in renal acid-base transport. Am J Physiol Renal Physiol, 300 (1): F11-23. [PMID:21048022]

* Weiner ID, Verlander JW. (2014) Ammonia transport in the kidney by Rhesus glycoproteins. Am J Physiol Renal Physiol, 306 (10): F1107-20. [PMID:24647713]

1. Endeward V, Cartron JP, Ripoche P, Gros G. (2008) RhAG protein of the Rhesus complex is a CO2 channel in the human red cell membrane. FASEB J, 22 (1): 64-73. [PMID:17712059]

2. Hemker MB, Cheroutre G, van Zwieten R, Maaskant-van Wijk PA, Roos D, Loos JA, van der Schoot CE, von dem Borne AE. (2003) The Rh complex exports ammonium from human red blood cells. Br J Haematol, 122 (2): 333-40. [PMID:12846905]

3. Mak DO, Dang B, Weiner ID, Foskett JK, Westhoff CM. (2006) Characterization of ammonia transport by the kidney Rh glycoproteins RhBG and RhCG. Am J Physiol Renal Physiol, 290 (2): F297-305. [PMID:16131648]

4. Ripoche P, Bertrand O, Gane P, Birkenmeier C, Colin Y, Cartron JP. (2004) Human Rhesus-associated glycoprotein mediates facilitated transport of NH(3) into red blood cells. Proc Natl Acad Sci USA, 101 (49): 17222-7. [PMID:15572441]

5. Westhoff CM, Ferreri-Jacobia M, Mak DO, Foskett JK. (2002) Identification of the erythrocyte Rh blood group glycoprotein as a mammalian ammonium transporter. J Biol Chem, 277 (15): 12499-502. [PMID:11861637]

6. Zidi-Yahiaoui N, Callebaut I, Genetet S, Le Van Kim C, Cartron JP, Colin Y, Ripoche P, Mouro-Chanteloup I. (2009) Functional analysis of human RhCG: comparison with E. coli ammonium transporter reveals similarities in the pore and differences in the vestibule. Am J Physiol, Cell Physiol, 297 (3): C537-47. [PMID:19553567]