Absence of CD47 in protein 4.2-deficient hereditary spherocytosis in man: an interaction between the Rh complex and the band 3 complex

Rh-RhAG/Ankyrin-R, a New Interaction Site between the Membrane Bilayer and the Red Cell Skeleton, Is Impaired by Rhnull-associated Mutation

“…Because Rh and RhAG deficiency is associated with stomato-spherocytosis of Rh null red cells, we and others have analyzed Rh complex expression in some HS red cells with primary defects in different skeletal or transmembrane proteins. Using this approach, a positive correlation between the expression levels of CD47 and protein 4.2 has been recently reported from the analysis of 4.2(Ϫ)HS red cells (21,22). However, as discussed in our introduction, the lack of protein 4.2 has no deleterious effect on the expression level and skeleton linkage of Rh and RhAG.…”

“…However, Rh and RhAG are associated with the skeleton of K562 cells and early erythroid precursors (16) (39). Potential interaction between CD47 and protein 4.2 is suggested from the deficiency of CD47 in 4.2(Ϫ)HS red cells (21,22). In the proposed model, the Rh complex and band 3 are associated with each other and the spectrin-based skeleton through their interaction with ankyrin-R. Bottom, in vitro translated, 35 S-labeled Ank-D2 was incubated with the GST fusion proteins and pulled-down with glutathione-Sepharose 4B beads, as described under "Material and Methods."…”

“…However, which protein of the Rh complex and which skeletal protein are involved in this vertical interaction remain unknown. Recently, an association between CD47 and protein 4.2 was indicated by the observation that RBCs with complete protein 4.2 deficiency (4.2(Ϫ)HS) exhibit a 80 -90% reduction of CD47 (21,22). However, CD47 linkage to the red cell skeleton was found to be independent of Rh and RhAG (20), and neither the expression level nor the Triton X-100 extraction of Rh and RhAG from the cell membrane were altered by the absence of protein 4.2 in 4.2(Ϫ)HS RBCs (22).…”

The Structure and Function of the Rh Antigen Complex

“…4 Recent findings indicate that Rh proteins mediate key interactions with the underlying cytoskeleton through protein 4.2 and ankyrin. [5][6][7] The erythrocyte Rh blood group proteins are well known because of their importance in blood transfusion, but recent functional studies and structural modeling reveal that the Rh blood group proteins are members of an ancient family of proteins involved in ammonia transport. [8][9][10][11] Non-erythroid Rh proteins have now been found in other tissues including the kidney, liver, brain, and skin 12-15 , in locations where ammonia production and elimination occurs.…”

Human Rhesus-associated glycoprotein mediates facilitated transport of NH 3 into red blood cells

“…However, it was also proposed recently that the Rh1 protein paralog of the green alga Chla- mydomonas reinhardtii might be regarded as a gas channel for CO 2 , because mutants lacking this protein grow only very slowly when cultured in high CO 2 conditions (48). That Rh proteins might transport NH 3 and͞or CO 2 is a possibility that should be further explored (32). Although still a matter of debate (49,50), current studies suggest that the water channel AQP1 may represent another example of protein permeable to gases, because it also substantially increases the permeability of the membrane to CO 2 (50,51) and NH 3 (33).…”