FIGURE 2.

NHE1 binds phosphoinositides through electrostatic interactions. Association of diC₈-PI(4,5)P₂ and diC₈-PI(3,4,5)P₃ with wild-type and mutant cNHE1 peptides (mutated residues are shown in A), as measured by surface plasmon resonance (B). Mutant cNHE1 binding to phospholipids, by membrane overlay assays (C). In control experiments binding to phosphatidylinositol monophosphates in the absence of cNHE1 peptides was occasionally observed (not shown), indicating a lack of binding specificity to these sites.