Ankyrin and band 3 differentially affect expression of membrane glycoproteins but are not required for erythroblast enucleation.
During late stages of mammalian erythropoiesis the nucleus undergoes chromatin condensation, migration to the plasma membrane, and extrusion from the cytoplasm surrounded by a segment of plasma membrane. Since nuclear condensation occurs in all vertebrates, mammalian erythroid membrane and cytoskeleton proteins were implicated as playing important roles in mediating the movement and extrusion of the nucleus. Here we use erythroid ankyrin deficient and band 3 knockout mouse models to show that band 3, but not ankyrin, plays an important role in regulating the level of erythroid cell membrane proteins, as evidenced by decreased cell surface expression of glycophorin A in band 3 knockout mice. However, neither band 3 nor ankyrin are required for enucleation. These results demonstrate that mammalian erythroblast enucleation does not depend on the membrane integrity generated by the ankyrin-band 3 complex.
Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. peng-ji@fsm.northwestern.edu
Peng
P
Ji
Harvey F
HF
Lodish
D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000235:genetics / Q000378:metabolism*; D017487:Ankyrins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D004900:Erythroblasts / Q000378:metabolism* / Q000648:ultrastructure; D004920:Erythropoiesis; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D018345:Mice, Knockout
D001457:Anion Exchange Protein 1, Erythrocyte; C491707:Ank1 protein, mouse; D017487:Ankyrins; D008562:Membrane Glycoproteins