A band 3-based macrocomplex of integral and peripheral proteins in the RBC membrane.
We have studied the membrane proteins of band 3 anion exchanger (AE1)-deficient mouse and human red blood cells. It has been shown previously that proteins of the band 3 complex are reduced or absent in these cells. In this study we show that proteins of the Rh complex are also greatly reduced (Rh-associated glycoprotein, Rh polypeptides, CD47, glycophorin B) or absent (LW). These observations suggest that the Rh complex is associated with the band 3 complex in healthy RBCs. Mouse band 3(-/-) RBCs differed from the human band 3-deficient RBCs in that they retained CD47. Aquaporin 1 was reduced, and its glycosylation was altered in mouse and human band 3-deficient RBCs. Proteins of the glycophorin C complex, and other proteins with independent cytoskeletal interactions, were present in normal or increased amounts. To obtain direct evidence for the association of the band 3 and the Rh protein complexes in the RBC, we examined whether Rh complex proteins were coimmunoprecipitated with band 3 from membranes. RhAG and Rh were found to be efficiently coimmunoprecipitated with band 3 from deoxycholate-solubilized membranes. Results suggest that band 3 forms the core of a macrocomplex of integral and peripheral RBC membrane proteins. The presence of these proteins in a single structural macrocomplex makes it likely that they have linked functional or regulatory roles. We speculate that this macrocomplex may function as an integrated CO(2)/O(2) gas exchange unit (metabolon) in the erythrocyte.
Bruce
Lesley J
LJ
Department of Biochemistry, University of Bristol, United Kingom.
Beckmann
Roland
R
Ribeiro
M Leticia
ML
Peters
Luanne L
LL
Chasis
Joel A
JA
Delaunay
Jean
J
Mohandas
Narla
N
Anstee
David J
DJ
Tanner
Michael J A
MJ
D019943:Amino Acid Substitution; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000032:analysis* / Q000172:deficiency* / Q000235:genetics; D015703:Antigens, CD / Q000097:blood; D051928:CD47 Antigen; D002352:Carrier Proteins / Q000097:blood; D004910:Erythrocyte Membrane / Q000737:chemistry*; D006801:Humans; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000097:blood; D051379:Mice; D018345:Mice, Knockout; D012204:Rh-Hr Blood-Group System
D001457:Anion Exchange Protein 1, Erythrocyte; D015703:Antigens, CD; D051928:CD47 Antigen; C497894:CD47 protein, human; D002352:Carrier Proteins; C497895:Cd47 protein, mouse; D046911:Macromolecular Substances; D008565:Membrane Proteins; D012204:Rh-Hr Blood-Group System