Fig. 4: Extreme membrane curvature and acidic lipids have a synergistic effect on SMP-mediated lipid transfer.
From: Insights into membrane association of the SMP domain of extended synaptotagmin
a, Schematic representation of SMP-mediated lipid transfer between curved ER-like and curved PM-like liposomes. b, Size distributions of PM-like acceptor liposomes with or without PI(4,5)P2 and PS prepared from extrusion through filters with 30 nm pores followed by DNA brick-assisted sorting. Diameters of liposomes were measured from negative-staining TEM images. Average diameters are presented as mean ± SD (n = 1258 and 1153 liposomes from left to right). c, Top, time courses of lipid transfer between ER-like donor liposomes and distinctly sized PM-like acceptor liposomes with or without PI(4,5)P2 and PS in the presence of SMP at 37 °C as assessed by dequenching of NBD-PE fluorescence. Bottom left, quantifications of NBD fluorescence after incubation for 15 min or 30 min. Bottom right, initial transfer rates. Data are presented as mean ± SD (n = 3 independent experiments). ** P < 0.01, *** P < 0.001, **** P < 0.0001 by two-way ANOVA with Bonferroni’s multiple comparisons test (bottom left) or by one-way ANOVA with Bonferroni’s multiple comparisons test (bottom right). P values: 2.3 × 10−4 (bottom left, 15 min), 2.4×10−7 (bottom left, 30 min), and 5.0 × 10−3 (bottom right) for [(SMP + 40-nm sorted PM-like liposomes) vs (SMP + 40-nm sorted PM-like liposomes no PS and PIP2)]; 1.8×10−5 (bottom left, 15 min), 1.6 × 10−8 (bottom left, 15 min), and 1.2 × 10−3 (bottom right) for [(SMP + 40-nm sorted PM-like liposomes) vs (SMP + 800-nm extruded PM-like liposomes)]. Source data are provided as a Source Data file.
