TY - JOUR
T1 - Analysis of the mobilities of band 3 populations associated with ankyrin protein and junctional complexes in intact murine erythrocytes
AU - Kodippili, Gayani C.
AU - Spector, Jeff
AU - Hale, Jacob
AU - Giger, Katie
AU - Hughes, Michael R.
AU - McNagny, Kelly M.
AU - Birkenmeier, Connie
AU - Peters, Luanne
AU - Ritchie, Ken
AU - Low, Philip S.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/2/3
Y1 - 2012/2/3
N2 - Current models of the erythrocyte membrane depict three populations of band 3: (i) a population tethered to spectrin via ankyrin, (ii) a fraction attached to the spectrin-actin junctional complex via adducin, and (iii) a freely diffusing population. Because many studies of band 3 diffusion also distinguish three populations of the polypeptide, it has been speculated that the three populations envisioned in membrane models correspond to the three fractions observed in diffusion analyses. To test this hypothesis, we characterized band 3 diffusion by single-particle tracking in wild-type and ankyrin- and adducin-deficient erythrocytes. We report that ∼40% of total band 3 in wild-type murine erythrocytes is attached to ankyrin, whereas ∼33% is immobilized by adducin, and ∼27% is not attached to any cytoskeletal anchor. Moredetailed analyses reveal that mobilities of individual ankyrinand adducin-tethered band 3 molecules are heterogeneous, varying by nearly 2 orders of magnitude and that there is considerable overlap in diffusion coefficients for adducin and ankyrin-tethered populations. Taken together, the data suggest that although the ankyrin- and adducin-immobilized band 3 can be monitored separately, significant heterogeneity still exists within each population, suggesting that structural and compositional properties likely vary considerably within each band 3 complex.
AB - Current models of the erythrocyte membrane depict three populations of band 3: (i) a population tethered to spectrin via ankyrin, (ii) a fraction attached to the spectrin-actin junctional complex via adducin, and (iii) a freely diffusing population. Because many studies of band 3 diffusion also distinguish three populations of the polypeptide, it has been speculated that the three populations envisioned in membrane models correspond to the three fractions observed in diffusion analyses. To test this hypothesis, we characterized band 3 diffusion by single-particle tracking in wild-type and ankyrin- and adducin-deficient erythrocytes. We report that ∼40% of total band 3 in wild-type murine erythrocytes is attached to ankyrin, whereas ∼33% is immobilized by adducin, and ∼27% is not attached to any cytoskeletal anchor. Moredetailed analyses reveal that mobilities of individual ankyrinand adducin-tethered band 3 molecules are heterogeneous, varying by nearly 2 orders of magnitude and that there is considerable overlap in diffusion coefficients for adducin and ankyrin-tethered populations. Taken together, the data suggest that although the ankyrin- and adducin-immobilized band 3 can be monitored separately, significant heterogeneity still exists within each population, suggesting that structural and compositional properties likely vary considerably within each band 3 complex.
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U2 - 10.1074/jbc.M111.294439
DO - 10.1074/jbc.M111.294439
M3 - Article
C2 - 22147703
AN - SCOPUS:84856697704
SN - 0021-9258
VL - 287
SP - 4129
EP - 4138
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 6
ER -