Fig. 1.

Moesin mediates receptor-independent phagocytosis. a Phagocytosis efficiency of DC2.4 cells transfected with non-specific (NS) or indicated siRNA. Data were presented as mean ± s.e.m. (for all following figures, unless noted otherwise), n = 200, collected from a total N = 4 independent experiments. Henceforth, “n” designates number of data points in each group, and “N” independent repeats of experiments. For indicated comparisons, ***p < 0.001, *<0.05 and ns p > 0.05 by one-way ANOVA with Scheffé post hoc. b Non-specific (NS) or Moesin shRNA-transfected DC2.4 cell single clones were immunoblotted with antibodies against Moesin and GAPDH (upper). Phagocytosis efficiency of the clones with high KD efficiency (indicated by red dot in the upper panel) is shown (lower). n = 50, N = 3. ***p < 0.001 by one-way ANOVA with Scheffé post hoc. c Left: Moesin, Ezrin, and Radixin (green) were visualized with antibodies along with actin cytoskeleton (phalloidin) on RAW264.7 cells incubated with 3 μm polystyrene beads. Structured Illumination Microscopy (SIM) was performed to obtain the fluorescence images. Scale bars, 5 µm. Right: Line profiles corresponding to fluorescence intensities of the respective ERM molecules and actin on an imaginary line across the indicated phagocytic cups. N = 6. d Schematic of Moesin and truncated Moesin fragments containing only FERM domain, or ITAM-YF mutations (Y191F + Y205F). e Moesin KD DC2.4 cells were rescued with the constructs in d by transient overexpression. Actin polymerization inhibitor Cytochalasin D was used as a negative control to establish baseline for phagocytosis. n ≥ 71 for each group. N = 3. For comparison between NS and NS CytoD group, ***p < 0.001 by Student’s t-test. For all other comparisons, ***p < 0.001 and ns p > 0.05 by one-way ANOVA with Scheffé post hoc