| Anion Exchanger 1 (Band 3) Is Required to Prevent Erythrocyte Membrane Surface Loss but Not to Form the Membrane Skeleton Cell, Volume 86, Issue 6, 20 September 1996, Pages 917-927 Luanne L Peters, Ramesh A Shivdasani, Shih-Chun Liu, Manjit Hanspal, Kathryn M John, Jennifer M Gonzalez, Carlo Brugnara, Babette Gwynn, Narla Mohandas, Seth L Alper, Stuart H Orkin and Samuel E Lux Summary The red blood cell (RBC) membrane protein AE1 provides high affinity binding sites for the membrane skeleton, a structure critical to RBC integrity. AE1 biosynthesis is postulated to be required for terminal erythropoiesis and membrane skeleton assembly. We used targeted mutagenesis to assess AE1 function in vivo. RBCs lacking AE1 spontaneously shed membrane vesicles and tubules, leading to severe spherocytosis and hemolysis, but the levels of the major skeleton components, the synthesis of spectrin in mutant erythroblasts, and skeletal architecture are normal or nearly normal. The results indicate that AE1 does not regulate RBC membrane skeleton assembly in vivo but is essential for membrane stability. We postulate that stabilization is achieved through AE1–lipid interactions and that loss of these interactions is a key pathogenic event in hereditary spherocytosis. Summary | Full Text | PDF (1893 kb) |
| Oligomeric states of spectrin in normal erythrocyte membranes: Biochemical and electron microscopic studies Cell, Volume 37, Issue 2, 1 June 1984, Pages 587-594 Shih-Chun Liu, Petra Windisch, Susie Kim and Jiri Palek Summary We estimated the relative amounts of oligomeric species of spectrin in 0°C red-cell-membrane extracts, including those released from spectrin-actinpolypeptide 4.1 complexes after mild urea treatment. Spectrin dimers, tetramers, and medium-size oligomers were the prominent species, accounting for 5%–10%, 45%–55%, and 25%–35% of spectrin, respectively. When examined by low-angle rotaryshadowing electron microscopy, these medium-size spectrin oligomers (e.g., hexamers, octamers, decamers, dodecamers, and quadecamers) appeared as polyskelions formed by head-to-head association of three to seven dimers. They were stable species capable of binding to, and subsequent release from, inside-out vesicles without degradation to tetramers or dimers. The data suggest that spectrin tetramers and medium-size oligomers coexist in the normal erythrocyte membrane as the primary native spectrin species. Summary | PDF (7310 kb) |
| Interaction of cytoskeletal proteins on the human erythrocyte membrane Cell, Volume 24, Issue 1, 1 April 1981, Pages 24-32 Daniel Branton, Carl M. Cohen and Jonathan Tyler | PDF (1417 kb) |
Copyright © 1996 The Biophysical Society. All rights reserved.
Biophysical Journal, Volume 70, Issue 3, 1534-1542, 1 March 1996
doi:10.1016/S0006-3495(96)79717-5
Research Article
D.E. Golan, J.D. Corbett, C. Korsgren, H.S. Thatte, S. Hayette, Y. Yawata and C.M. Cohen
Band 4.2 is a human erythrocyte membrane protein of incompletely characterized structure and function. Erythrocytes deficient in band 4.2 protein were used to examine the functional role of band 4.2 in intact erythrocyte membranes. Both the lateral and the rotational mobilities of band 3 were increased in band 4.2-deficient erythrocytes compared to control cells. In contrast, the lateral mobility of neither glycophorins nor a fluorescent phospholipid analog was altered in band 4.2-deficient cells. Compared to controls, band 4.2-deficient erythrocytes manifested a decreased ratio of band 3 to spectrin, and band 4.2-deficient membrane skeletons had decreased extractability of band 3 under low-salt conditions. Normal band 4.2 was found to bind to spectrin in solution and to promote the binding of spectrin to ankyrin-stripped inside-out vesicles. We conclude that band 4.2 provides low-affinity binding sites for both band 3 oligomers and spectrin dimers on the human erythrocyte membrane. Band 4.2 may serve as an accessory linking protein between the membrane skeleton and the overlying lipid bilayer.