A new chapter in Rh research: Rh proteins are ammonium transporters

Occasionally, an original research paper has an unusually significant impac t on a particular research field. Such a paper, published recently in Natur e Genetics, describes the uncovering of the functional role of the Rh prote in family - the proteins that express the Rh blood group antigens, Marini e t al.(1) demonstrate how two human Rh glycoproteins can correct ammonium tr ansport deficiency in mutant yeast cells. Rh proteins are therefore ammoniu m transporters - a role that, in vertebrates, has remained previously uncha racterized. These data herald a new era in Rh protein research, beyond thei r role as blood group antigens, and into the characterization of ammonium t ransport mechanisms, notably in the kidney.