Journal: EMBO Reports
Article Title: Myddosome clustering in IL ‐1 receptor signaling regulates the formation of an NF‐kB activating signalosome
doi: 10.15252/embr.202357233
Figure Lengend Snippet: A, B Top, TIRF images of fixed EL4‐MyD88‐GFP cells incubated with IL‐1 functionalized SLBs for 30 min and stained with antibodies against pp65 (A) or pIKK (B). Scale bar, 5 μm. Region of interest (red box, merge image) shows an example of MyD88‐GFP puncta that colocalizes with pp65 (A) or pIKK (B) puncta. Bottom, 2D histograms of the distribution of MyD88 puncta intensity and associated pp65 (A) or pIKK (B) staining intensity. Linear fit is shown as a blue line superimposed on 2D histograms (Pearson correlation coefficient, R , of linear fit labeled on 2D histograms). Blue‐shaded regions on scatter plot high MyD88 puncta classified as clustered Myddosomes. Bottom right, zoomed images of the region of interest (red box overlaid merge image, top) show MyD88‐GFP channel and associated pp65 (A) and pIKK (B) channel (pp65/pIKK images are displayed with Fire LUT). Red data points on the 2D histogram are from indicated puncta in the MyD88‐GFP image (numbered red arrows). Scale bar, 1 μm. C, D TIRF images of fixed EL4‐MyD88‐GFP cells incubated with partitioned IL‐1 functionalized SLBs (2.5 μm top row and 1 μm bottom row) and stained with anti‐pp65 (C) or anti‐pIKK (D). Region of interest (red box overlaid merge image) shows examples of MyD88‐GFP puncta that colocalize with pp65 (A) or pIKK (B) puncta. Scale bar, 5 μm. Far right, zoomed image of pp65 (C) or pIKK (D) puncta (from region of interest overlaid merge image) displayed with Fire LUT. Scale bar, 1 μm. E, F 2D histogram of MyD88‐GFP puncta intensity and associated pp65 (E) or pIKK (F) staining intensity on 2.5 and 1 μm grids. Linear fit is shown as a blue line superimposed on 2D histograms (Pearson correlation coefficient, R , of linear fit labeled on 2D histograms). G, H Quantification of mean pp65 (G) or pIKK (H) staining intensity for puncta classifieds as single or clustered Myddosomes, and MyD88 puncta formed on 2.5 and 1 μm grids. The normalized mean intensity for clusters, single Myddosomes MyD88 puncta on 2.5 and 1 μm grids are the following: for pp65 0.318 ± 0.044, 0.163 ± 0.009, 0.059 ± 0.005 and 0.057 ± 0.008; for pIKK 0.393 ± 0.051, 0.130 ± 0.004, 0.037 ± 0.006 and 0.035 ± 0.007 (a.u., mean ± SEM, mean value states in the order they appear on plot, left to right). Violin plots show the distribution of all segmented MyD88 puncta. Data points superimposed on the violin plots are the averages from independent experiments. P ‐values are * < 0.05, *** < 0.001, **** < 0.0001. Bars represent mean ± SEM ( n = 3–4 biological replicates for pp65, with 10,273, 14,009 and 2,675 puncta off grid, on 2.5 μm and 1 μm grid measured in total across all replicates; n = 4–5 biological replicates for pIKK, with 2,375, 35,496 and 59,593 puncta off grid, on 2.5 μm and 1 μm grid measured in total across all replicates). Statistical significance is determined using unpaired two‐tailed Student's t ‐test. Source data are available online for this figure.
Article Snippet: We acquired 3D structured illumination microscopy of fixed EL4 cells on a Zeiss Elyra 7 microscope equipped with 405, 488, 561, and 642 nm laser lines for excitation.
Techniques: Incubation, Staining, Labeling, Two Tailed Test