b) The affinity of the UVRAG-C2 domain for phospholipids was assessed using a protein-lipid overlay assay. The left panel indicates the identity of lipid species on PtdIns strips. Bacterial-purified GST fusion of UVRAG-C2 (wild type, WT), but not GST, binds PtdIns(3) P, PtdIns(4) P and PtdIns(5) P. The K78A/R82A mutant of C2 is defective for phospholipid-binding, whereas the K87A/N88A mutant is partially impaired. Binding of the FYVE and PH domains of Hrs and FAPP1, respectively, to PtdIns(3) P and PtdIns(4) P served as quality controls (right). PE, phosphatidylethanolamine; PC, phosphatidylcholine; LPA, lysophosphatidic acid; LPC, lysophosphatidylcholine; S1P, sphingosine 1-phosphate; PA, phosphatidic acid; PS, phosphatidylserine. 