Figure 1: QF-FRL of liposomal replicas.
From: Yeast and mammalian autophagosomes exhibit distinct phosphatidylinositol 3-phosphate asymmetries
(a) QF-FRL of unilamellar liposomes containing 95 mol% of phosphatidylcholine and 5 mol% of a phosphoinositide, labelled with GST-PX. Only liposomes containing PtdIns(3)P were labelled intensely. GST-PXR58A, a PX-domain mutant that does not bind PtdIns(3)P, yielded virtually no labelling in PtdIns(3)P-containing liposomes. Scale bar, 0.2 μm. (b) QF-FRL of unilamellar liposomes containing 0–5 mol % of PtdIns(3)P. Scale bar, 0.2 μm. The labelling density increased roughly in proportion to the PtdIns(3)P content of the liposomes. The experiment was repeated twice and the number of colloidal gold particles per μm2 was measured in more than 75 randomly selected liposomes. Values for all concentrations are statistically different from those in the adjacent conditions (for example, 1 versus 2 mol%; mean±s.e.m.; Student’s t-test; P<0.05).
