Figure 6. Reconstitution of the NCX1, NKA, and InsP₃R Complex Requires Ankyrin-B.

(A) Purified NKA (α/β subunits), InsP₃R, NCX1, and ankyrin-B membrane-binding domain (ANKB MBD) were examined by SDS-PAGE and Coomassie blue.

(B) Stained gel of control beads and beads plus purified InsP₃R.

(C) NKA and NCX1 were ¹²⁵I-labeled and incubated with control Dynabeads or Dynabeads coated with InsP₃R with or without ankyrin-B membrane-binding domain. Bound protein was analyzed by a gamma-counter (C) and by SDS-PAGE and phosphorimaging (not shown; see Materials and Methods for protein measurement, n = 3, p < 0.05).