Attaches integral membrane proteins to cytoskeletal elements; binds to the erythrocyte membrane protein band 4.2, to Na-K ATPase, to the lymphocyte membrane protein GP85, and to the cytoskeletal proteins fodrin, tubulin, vimentin and desmin. Erythrocyte ankyrins also link spectrin (beta chain) to the cytoplasmic domain of the erythrocytes anion exchange protein; they retain most or all of these binding functions. In skeletal muscle, isoform Mu7 together with obscurin may provide a molecular link between the sarcoplasmic reticulum and myofibrils. Interacts with a number of integral membrane proteins and cytoskeletal proteins. Interacts (via N-terminus) with SPTB/spectrin (beta chain). Interacts (via N-terminus ANK repeats) with SLC4A1/erythrocyte membrane protein band 3 (via cytoplasmic N-terminus). Also interacts with TTN/titin. Isoform Mu17 interacts with OBSCN isoform 3/obscurin. Interacts with HIF1AN (By similarity). Probably the other erythrocyte (Er) isoforms, are located near the surface of erythrocytic plasma membrane. The 55 kDa regulatory domain is involved in regulating binding of SPTB/spectrin (beta chain) and SLC4A1/erythrocyte membrane protein band 3. The ANK repeat region forms a spiral around a large central cavity and is involved in binding of ion transporters. The tandem configuration of the two ZU5 and the UPA domains forms a structural supramodule termed ZZU. ZU5-1 mediates interaction with beta-spectrin, and the ZU5-1/UPA interface is required for ankyrin's function other than binding to spectrin (By similarity). Regulated by phosphorylation. Acylated by palmitic acid group(s). Hydroxylated by HIF1AN at several asparagine and 1 aspartate residue within ANK repeat region; hydroxylation seems to increase the conformational stability of this region and may also modulate protein-protein interactions mediated by the ANK repeat region. Produced by alternative promoter usage. Produced by alternative splicing of isoform Er1. Incomplete sequence. Produced by alternative splicing of isoform Er1. Incomplete sequence. Produced by alternative splicing of isoform Er1. Produced by alternative splicing of isoform Er1. Produced by alternative splicing of isoform Er1. Produced by alternative promoter usage. Produced by alternative splicing of isoform Mu7.