The MNS glycophorin variant GP.Mur affects differential erythroid expression of Rh/Rh AG transcripts.

Background The band 3 macrocomplex (also known as the ankyrin-associated complex) on the red cell membrane comprises two interacting subcomplexes: a band 3/glycophorin A subcomplex, and a Rh/Rh AG subcomplex. Glycophorin B ( GPB) is a component of the Rh/Rh AG subcomplex that is also structurally associated with glycophorin A ( GPA). Expression of glycophorin B-A-B hybrid GP.Mur enhances band 3 expression and is associated with lower levels of Rh-associated glycoprotein (Rh AG) and Rh polypeptides. The goal of this study was to determine whether GP.Mur influenced erythroid Rh/Rh AG expression at the transcript level. Materials and Methods GP.Mur was serologically determined in healthy participants from Taitung County, Taiwan. RNA was extracted from the reticulocyte-enriched fraction of peripheral blood, followed by reverse transcription and quantitative PCR for Rh AG, RhD and RhCcEe. Results Quantification by real-time PCR revealed significantly fewer Rh AG and RhCcEe transcripts in the reticulocytes from subjects with homozygous GYP*Mur. Independent from GYP.Mur, both Rh AG and RhD transcript levels were threefold or higher than that of RhCcEe. Also, in GYP.Mur and the control samples alike, direct quantitative associations were observed between the transcript levels of Rh AG and RhD, but not between that of Rh AG and RhCcEe. Conclusion Erythroid RhD and RhCcEe were differentially expressed at the transcript levels, which could be related to their different degrees of interaction or sensitivity to Rh AG. Further, the reduction or absence of glycophorin B in GYP.Mur erythroid cells affected transcript expressions of Rh AG and RhCcEe. Thus, GPB and GP.Mur differentially influenced Rh/Rh AG expressions prior to protein translation. [ABSTRACT FROM AUTHOR]