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 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 CO2/O2 gas exchange unit (metabolon) in the erythrocyte.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Wellcome Trust, the Institut National de la Sante et de la Recherche Medicale (Unite 473) alone or jointly with the Association Francaise contre les Myopathies (project no. 4MR09F). (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 815390
- Report Number(s):
- LBNL-53021; R&D Project: 80UY01; TRN: US200319%%198
- Journal Information:
- The Journal of the American Society of Hematology, 'Blood', Vol. 101, Issue 10; Other Information: Journal Publication Date: May 15, 2003; PBD: 18 Jun 2003
- Country of Publication:
- United States
- Language:
- English
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