Rh Family, C Glycoprotein (RHCG)

The Rhesus blood group antigens are defined by a complex association of membrane polypeptides that includes the nonglycosylated Rh proteins RhD and RhCE, and the RhAG glycoprotein (RHAG), which is strictly required for cell surface expression of these antigens. RhAG and the Rh polypeptides are erythroid-specific transmembrane proteins belonging to the same family (36% identity). Sequence analysis predicted that RHCG is a 479-amino acid, negatively charged, hydrophobic, 12-pass transmembrane protein that shares 77% identity and 90% similarity with the mouse sequence. RHCG contains 3 potential N-glycosylation motifs, one of which is located in the N-terminal exoloop, and it has an elongated C-terminal segment compared with erythroid Rhesus homologs.