Figure 9. Binding of ORP2 to phosphoinositides.

Liposome pull-down assay was carried out as described in [26]. GST–ORP2 fusion protein (black bars) bound to glutathione–Sepharose beads was incubated with vesicles consisting of unlabelled PC, [¹⁴C]PC and 1 mol% of the indicated phosphoinositide. ‘PC’ indicates binding to liposomes that consist of PC only. GST was used as a negative control (values subtracted from the results) and PH domain of PLCδ fused to GST (white bars) as a positive control. The radioactivity associated with the beads was measured by liquid-scintillation counting. The lipid binding is expressed as the percentage of total radioactivity recovered (mean±S.E.M., n=2).