Figure 5

The C-terminus of P2X2, but not of P2X3, directly binds phosphoinositides. A) Alignment of the proximal C-termini of rat P2X2 and P2X3 subunits showing intracellular basic residues candidates for lipid binding. The dashed lines delineate the sequences of the peptides used in the lipid binding assay. B) Positions of the different lipids spotted on the membrane. C) Binding pattern of GST protein alone, GST-P2X2 (F355-T372) and GST-P2X3 (F346-T364) shows that the sequence from P2X2, but not from P2X3, directly binds several anionic phospholipids including PIP₂ and PIP₃.